Kirtland Air Force Base

Abstract A procedure for forming hierarchical groups of mutually exclusive subsets, each of which has members that are maximally similar with respect to specified characteristics, is suggested for use in large-scale (n > 100) studies when a precise optimal solution for a specified number of groups is not practical. Given n sets, this procedure permits their reduction to n − 1 mutually exclusive sets by considering the union of all possible n(n − 1)/2 pairs and selecting a union having a maximal value for the functional relation, or objective function, that reflects the criterion chosen by the investigator. By repeating this process until only one group remains, the complete hierarchical structure and a quantitative estimate of the loss associated with each stage in the grouping can be obtained. A general flowchart helpful in computer programming and a numerical example are included.

CONTEXT: Although cholesterol-reducing treatment has been shown to reduce fatal and nonfatal coronary disease in patients with coronary heart disease (CHD), it is unknown whether benefit from the reduction of low-density lipoprotein cholesterol (LDL-C) in patients without CHD extends to individuals with average serum cholesterol levels, women, and older persons. OBJECTIVE: To compare lovastatin with placebo for prevention of the first acute major coronary event in men and women without clinically evident atherosclerotic cardiovascular disease with average total cholesterol (TC) and LDL-C levels and below-average high-density lipoprotein cholesterol (HDL-C) levels. DESIGN: A randomized, double-blind, placebo-controlled trial. SETTING: Outpatient clinics in Texas. PARTICIPANTS: A total of 5608 men and 997 women with average TC and LDL-C and below-average HDL-C (as characterized by lipid percentiles for an age- and sex-matched cohort without cardiovascular disease from the National Health and Nutrition Examination Survey [NHANES] III). Mean (SD) TC level was 5.71 (0.54) mmol/L (221 [21] mg/dL) (51 st percentile), mean (SD) LDL-C level was 3.89 (0.43) mmol/L (150 [17] mg/dL) (60th percentile), mean (SD) HDL-C level was 0.94 (0.14) mmol/L (36 [5] mg/dL) for men and 1.03 (0.14) mmol/L (40 [5] mg/dL) for women (25th and 16th percentiles, respectively), and median (SD) triglyceride levels were 1.78 (0.86) mmol/L (158 [76] mg/dL) (63rd percentile). INTERVENTION: Lovastatin (20-40 mg daily) or placebo in addition to a low-saturated fat, low-cholesterol diet. MAIN OUTCOME MEASURES: First acute major coronary event defined as fatal or nonfatal myocardial infarction, unstable angina, or sudden cardiac death. RESULTS: After an average follow-up of 5.2 years, lovastatin reduced the incidence of first acute major coronary events (1 83 vs 116 first events; relative risk [RR], 0.63; 95% confidence interval [CI], 0.50-0.79; P<.001), myocardial infarction (95 vs 57 myocardial infarctions; RR, 0.60; 95% CI, 0.43-0.83; P=.002), unstable angina (87 vs 60 first unstable angina events; RR, 0.68; 95% CI, 0.49-0.95; P=.02), coronary revascularization procedures (157 vs 106 procedures; RR, 0.67; 95% CI, 0.52-0.85; P=.001), coronary events (215 vs 163 coronary events; RR, 0.75; 95% CI, 0.61-0.92; P =.006), and cardiovascular events (255 vs 194 cardiovascular events; RR, 0.75; 95% CI, 0.62-0.91; P = .003). Lovastatin (20-40 mg daily) reduced LDL-C by 25% to 2.96 mmol/L (115 mg/dL) and increased HDL-C by 6% to 1.02 mmol/L (39 mg/dL). There were no clinically relevant differences in safety parameters between treatment groups. CONCLUSIONS: Lovastatin reduces the risk for the first acute major coronary event in men and women with average TC and LDL-C levels and below-average HDL-C levels. These findings support the inclusion of HDL-C in risk-factor assessment, confirm the benefit of LDL-C reduction to a target goal, and suggest the need for reassessment of the National Cholesterol Education Program guidelines regarding pharmacological intervention.

We present the impact tests that preceded the most recent operational upgrades to the land surface model used in the National Centers for Environmental Prediction (NCEP) mesoscale Eta model, whose operational domain includes North America. These improvements consist of changes to the “Noah” land surface model (LSM) physics, most notable in the area of cold season processes. Results indicate improved performance in forecasting low‐level temperature and humidity, with improvements to (or without affecting) the overall performance of the Eta model quantitative precipitation scores and upper air verification statistics. Remaining issues that directly affect the Noah LSM performance in the Eta model include physical parameterizations of radiation and clouds, which affect the amount of available energy at the surface, and stable boundary layer and surface layer processes, which affect surface turbulent heat fluxes and ultimately the surface energy budget.

Abstract A procedure for forming hierarchical groups of mutually exclusive subsets, each of which has members that are maximally similar with respect to specified characteristics, is suggested for use in large-scale (n > 100) studies when a precise optimal solution for a specified number of groups is not practical. Given n sets, this procedure permits their reduction to n − 1 mutually exclusive sets by considering the union of all possible n(n − 1)/2 pairs and selecting a union having a maximal value for the functional relation, or objective function, that reflects the criterion chosen by the investigator. By repeating this process until only one group remains, the complete hierarchical structure and a quantitative estimate of the loss associated with each stage in the grouping can be obtained. A general flowchart helpful in computer programming and a numerical example are included.

Two-dimensional image moments with respect to Zernike polynomials are defined, and it is shown how to construct an arbitrarily large number of independent, algebraic combinations of Zernike moments that are invariant to image translation, orientation, and size. This approach is contrasted with the usual method of moments. The general problem of two-dimensional pattern recognition and three-dimensional object recognition is discussed within this framework. A unique reconstruction of an image in either real space or Fourier space is given in terms of a finite number of moments. Examples of applications of the method are given. A coding scheme for image storage and retrieval is discussed.

We present a novel, self-referencing interferometric technique for measuring the amplitude and the phase of ultrashort optical pulses. The apparatus uses a collinear geometry that requires no moving components. The phase-retrieval procedure is noniterative and rapid and uses only two one-dimensional Fourier transforms. We apply the technique to characterize ultrashort pulses from a mode-locked Ti:sapphire oscillator.

A single lasing mode driven by a three-level ``quantum-beat'' atomic configuration can show gain without population inversion or optical absorption into an excited state without spontaneous or stimulated emission.

We have tested the T helper cell (TH) potential of asymptomatic, HIV seropositive (HIV+) patients, using an in vitro assay for IL-2 production. Peripheral blood leukocytes (PBL) from 74 HIV+ patients and 70 HIV- control donors were tested for TH function when stimulated with influenza A virus (FLU), tetanus toxoid (TET), HLA alloantigens (ALLO), or PHA. Of the HIV+ patients, four different response patterns were observed: (a) patients who responded to all four stimuli (16%); (b) patients who were selectively unresponsive to FLU and TET, but responded to ALLO and PHA (54%); (c) patients who were unresponsive to FLU, TET, or ALLO, but responsive to PHA (16%); and (d) patients who failed to respond to any of these stimuli (14%). Our results indicate a time-dependent progression from a stage responsive to all four stimuli to a stage unresponsive to any of the stimuli tested, progressing in the order outlined above. The earliest TH defect is the loss of responses to FLU and TET, indicating a selective defect in CD4+ MHC self-restricted TH function. The later loss of ALLO and PHA IL-2 responses suggests more severe TH dysfunction involving both CD4+ and CD8+ T cells. None of these patterns of TH unresponsiveness in asymptomatic HIV+ individuals were correlated with CD4+ cell numbers nor with Walter Reed staging criteria. This study indicates that the in vitro TH assay used can detect multiple stages of immune dysregulation early in the course of HIV infection and raises the possibility that staging of HIV+ patients should include in vitro TH functional analyses of the type described here.

A partially coherent quasi-monochromatic Gaussian laser beam propagating in atmospheric turbulence is examined by using a derived analytic expression for the cross-spectral density function. Expressions for average intensity, beam size, phase front radius of curvature, and wave-front coherence length are obtained from the cross-spectral density function. These results provide a model for a free-space laser transmitter with a phase diffuser used to reduce pointing errors.

The Electric Fields and Waves (EFW) Instruments on the two Radiation Belt Storm Probe (RBSP) spacecraft (recently renamed the Van Allen Probes) are designed to measure three dimensional quasi-static and low frequency electric fields and waves associated with the major mechanisms responsible for the acceleration of energetic charged particles in the inner magnetosphere of the Earth. For this measurement, the instrument uses two pairs of spherical double probe sensors at the ends of orthogonal centripetally deployed booms in the spin plane with tip-to-tip separations of 100 meters. The third component of the electric field is measured by two spherical sensors separated by ∼15 m, deployed at the ends of two stacer booms oppositely directed along the spin axis of the spacecraft. The instrument provides a continuous stream of measurements over the entire orbit of the low frequency electric field vector at 32 samples/s in a survey mode. This survey mode also includes measurements of spacecraft potential to provide information on thermal electron plasma variations and structure. Survey mode spectral information allows the continuous evaluation of the peak value and spectral power in electric, magnetic and density fluctuations from several Hz to 6.5 kHz. On-board cross-spectral data allows the calculation of field-aligned wave Poynting flux along the magnetic field. For higher frequency waveform information, two different programmable burst memories are used with nominal sampling rates of 512 samples/s and 16 k samples/s. The EFW burst modes provide targeted measurements over brief time intervals of 3-d electric fields, 3-d wave magnetic fields (from the EMFISIS magnetic search coil sensors), and spacecraft potential. In the burst modes all six sensor-spacecraft potential measurements are telemetered enabling interferometric timing of small-scale plasma structures. In the first burst mode, the instrument stores all or a substantial fraction of the high frequency measurements in a 32 gigabyte burst memory. The sub-intervals to be downloaded are uplinked by ground command after inspection of instrument survey data and other information available on the ground. The second burst mode involves autonomous storing and playback of data controlled by flight software algorithms, which assess the “highest quality” events on the basis of instrument measurements and information from other instruments available on orbit. The EFW instrument provides 3-d wave electric field signals with a frequency response up to 400 kHz to the EMFISIS instrument for analysis and telemetry (Kletzing et al. Space Sci. Rev. 2013).

Advances in prehospital care and trauma resuscitation have enabled the early survival of many injured patients who previously had a high chance of dying at the accident scene or en route to the hospital. The change in the spectrum of injury severity, characterized by high-energy blunt trauma with multiple-organ injury and fractures, and the emergence of semiautomatic handguns with multiple penetrating wounds, present new challenges to all surgeons. In conventional trauma care, definitive control and repair of all injuries may be accomplished in the immediate postinjury setting; however, the physiologic derangements of the massive shock state caused by the aforementioned injury patterns often lead to a fully repaired but dead patient. In response to these catastrophic challenges, the concept of “damage control” as a treatment merely to control but not definitively repair injuries has arisen. This term was originally coined by the United States Navy, in reference to “the capacity of a ship to absorb damage and maintain mission integrity.”1 In the patient with multiple injuries who is exsanguinating, this has been paraphrased to indicate the sum total of the maneuvers necessary to ensure patient survival above all else. 2 Definitive control of hemorrhage by pressure is not new to surgery. Pringle first enunciated the principles of compression and hepatic packing for control of portal venous hemorrhage in 1908. 3 This was modified by Halsted, who inserted rubber sheets between the liver and packs to protect hepatic parenchyma. 4 Military experience in World War II and Vietnam discouraged this practice. 5 As early as 1963, however, Shaftan et al. observed that to limit the mortality of liver injury, both faster and better resuscitation and better treatment of the wounds were necessary. 6 In 1979, Calne et al. described four cases in which massive exsanguinating hemorrhage from the liver was temporarily controlled with gauze packing, enabling safe transfer and definitive management at a more appropriate institution. 7 In 1983, Stone and associates popularized the technique of truncation of laparotomy, establishment of intra-abdominal pack tamponade, and then completion of definitive surgical repair later, once coagulation had returned to an acceptable level. This proved to be lifesaving in previously nonsalvageable situations. 8 Damage control, abbreviated laparotomy specifically to salvage trauma patients with exsanguination, was described at several institutions almost simultaneously in the early 1990s. 9–11 Rotondo et al. found a remarkable salvage rate of over 70% in a limited number of patients treated with damage control for abdominal vascular injury and massive shock, hypothermia, and acidosis. Since then, damage control has gained widespread use throughout North America, Israel, and South Africa. Recently, a review by Rotondo and Zonies identified 961 damage control patients in the literature, with 50% mortality and 40% morbidity overall. 12 Subsequent reports have expanded this list to over 1,000 patients (Table 1). Table 1: Cumulative Review of Damage ControlDamage control as currently practiced has three separate components. The first is abbreviated resuscitative surgery for rapid control of hemorrhage and contamination. This is obtained as quickly as possible in the operating room, but traditional repairs are deferred in favor of rapid measures that control hemorrhage, restore flow where needed, and control or contain contamination. Intra-abdominal packing and temporary abdominal closure complete this truncated first and critical step (Part I). The patient is then moved to the intensive care unit, where Part II consists of ongoing core rewarming, correction of coagulopathy, fluid resuscitation and optimization of hemodynamic status, as well as reexamination to diagnose all injuries. When normal physiology has been restored, reexploration is undertaken for definitive management of injuries and abdominal closure (Part III). 9,13 Increases in firearm violence present a new source of challenge to which damage control techniques are often applicable. In one study from the United States in an urban setting, firearm-related homicide increased by 123% over 5 years, and the number of victims who died at the scene rose from 5% to 34%. This was despite the designation of six trauma centers in that county, reflecting a shift toward high-velocity, high-caliber weaponry. 14 It has been apparent in our clinical practice for some time that inner city street weaponry and wounding patterns are changing, with multiple-shot injury patterns becoming much more common. These patients often present with multicavitary sites of exsanguination, and damage control techniques have assumed a prominent role in their initial management. This article reviews the principles of damage control as a series of linked surgical maneuvers, designed to address the physiologic abnormalities first, followed by a secondary resuscitative phase, and then the definitive surgical procedures themselves. Though damage control was traditionally described for massive abdominal trauma with vascular injury, recent applications in the chest and even to peripheral vascular injury have been reported. 15–17 GENERAL CONSIDERATIONS AND SECONDARY RESUSCITATION The goal of the damage control approach is to preserve the living patient. The triad of hypothermia, acidosis, and coagulopathy in the patient with multiple injuries is often lethal; Ferrara et al. reported 90% mortality in patients with these findings requiring massive transfusion. 18 Rewarming, replacement of coagulation factors, and fluid and blood resuscitation are critical to counter this state. 11 Damage control encompasses this algorithm, emphasizing rapid but definitive hemostasis, closing all hollow viscus injuries or performing only essential bowel resections, and delaying the more traditional or standard reconstruction until after the patient has been stabilized and all physiologic parameters have been corrected. Primary Operation and Hemorrhage Control The initial damage control laparotomy (Part I) includes five components: control of hemorrhage, exploration, control of contamination, definitive packing, and rapid abdominal closure. 19 An important distinction should be made between resuscitative and therapeutic packing. Resuscitative packing with manual compression of a bleeding site is often used as an initial short-term (minutes) measure to control or minimize blood loss while repairing other higher priority injuries or “catching up.”20 Therapeutic packing, in contrast, provides tamponade of bleeding when it is surgically unmanageable or a coagulopathy has developed. This is used to enable a longer period of resuscitation, to give the body time to correct the metabolic derangements mentioned above, 21 and to access other means of definitive vascular control such as therapeutic angiography. The decision to truncate the procedure should be made early when, in the judgment of the surgeon, definitive repair is either likely to exceed the patient’s physiologic reserve or is technically impossible. 22 The indications for damage control have recently been described in six general categories (Table 2). 23 Critical variables include the surgeon’s ability to control hemorrhage, the severity of the injuries, and the presence of other associated injuries. Packing as a therapeutic procedure should be implemented well before massive blood loss (10–15 units of packed red blood cells) has occurred. 24,25 Other variables that have been identified as significant include severe injury (Injury Severity Score >35), hypotension (shock in excess of 70 minutes), hypothermia (temperature <34°C), coagulopathy (prothrombin time >19 seconds or partial thromboplastin time >60 seconds), and acidosis (pH <7.2). 5,26,27 With these caveats, the need for packing as a planned therapeutic approach can often be anticipated preoperatively. Packing does not take the place of vessel ligation or clamping. Most vessels can be rapidly isolated, repaired, ligated, or shunted if necessary. Once definitive vascular control is obtained, packing of all raw or dissected surfaces is done. Occasionally, with injury to the liver, pelvis, or large muscle beds, packing must be done and prompt angiography performed to control these intraparenchymal or intramuscular vessels. Regardless of the bleeding source, expeditious vascular control is of paramount importance. Without it, exsanguination is ensured. Table 2: Indications for the Damage Control ApproachHypothermia, Acidosis, and Coagulopathy: The Lethal Triad Hypothermia Thermal homeostasis depends on a balance between the factors governing heat loss—conduction, convection, evaporation, and radiation—and the body’s ability to generate and maintain metabolic energy. Heat loss begins at the moment of traumatic insult, and is exacerbated by extenuating circumstances such as shock and low perfusion, prolonged exposure, immobility of the acutely injured patient, and extremes of age. In the absence of a preemptive treatment approach, this process continues in the emergency department, where the patient is unclothed and left fully exposed, with a resultant patient–room temperature gradient of 15°C. In this setting, measurable temperature loss occurs in up to 92% of patients. 28,29 Clinically significant hypothermia is considered present when the core temperature is less than 35°C, 30 and temperature less than 34°C has been linked with a need for early therapeutic packing. 27 Hypothermia has been reported in 21% of all severely injured patients, and up to 46% of trauma victims requiring laparotomy leave the operating room hypothermic. 29,31 Clinically, hypothermic patients have significantly greater fluid, transfusion, vasopressor and inotropic requirements, resulting in higher incidences of organ dysfunction, mortality, and markedly prolonged intensive care unit stay. 31–35 Hypothermia itself may not be the cause of these conditions, but it reflects the magnitude of the original injury and the associated shock state. Passive external rewarming techniques include patient shivering and simple covering of the patient to minimize convective heat loss. Active external rewarming techniques include fluid-circulating heating blankets, convective warm air blankets, and radiant warmers. Paradoxically, the initial response to these techniques may be adverse, as fluid shifts and changes in vascular tone decrease venous return, lower blood pressure, and diminish cardiac output. The return of cold, acidotic blood to the central circulation may initially lower core temperature, and has been associated with ventricular fibrillation during rewarming. 36,37 Active core rewarming techniques include warmed airway gases, heated peritoneal or pleural lavage, warmed intravenous fluid infusion, and extracorporeal rewarming. Cold (i.e., room temperature) intravenous fluid administration has been invoked as the fastest way of accelerating hypothermia. 28 Countercurrent heat exchange mechanisms have enabled the rapid infusion of warmed banked blood products. 38 Extracorporeal rewarming techniques may be limited by the need for anticoagulation. Continuous arteriovenous rewarming, however, can be accomplished with a heparin-bonded circuit without a pump that may eliminate this limitation. This process is driven by the patient’s blood pressure; hence, its effectiveness is limited by hypotension. This technique can accomplish rewarming at a rate of 4° to 5°C per hour, which is far more efficient than the 1° to 2°C possible with other methods. Because warmed blood is sent directly to core organs, continuous arteriovenous rewarming rapidly increases core temperature by nonshivering thermogenesis, which may increase metabolic effectiveness. 36 Acidosis Acidosis associated with hypovolemic shock contributes to coagulopathic bleeding, which worsens the shock state. Correction requires not only control of hemorrhage but also optimization of oxygen delivery, blood and of cardiac output. a of resuscitative have been that conventional and venous oxygen and of coagulation factors and by fluid resuscitation, total and hypothermia, the severity of injury, shock, and metabolic acidosis may all to the of normal The clinical of coagulopathy is not by that other than the of factors and the number and of may be in the of Hypothermia in the patient to of and coagulation of the of these is by of and partial thromboplastin in hypothermic conditions, even where coagulation factors are to be is performed at than at the patient’s core temperature, and may the of in hypothermia to prolonged bleeding from a in in by temperature may also the and of despite the replacement of is often between and bleeding in patients who have massive transfusion, and the presence of hemorrhage in this is an for even with a in hypothermic has been to the of in the and of may also lead to is a simple that can coagulation abnormalities and give and that is not from coagulation the of with the coagulation from initial and to It is for use in the operating room, the of coagulopathy, and may be an early of the need for in patients with blunt of the damage control approach to coagulopathic bleeding have been an initial by et al. in in mortality with et al. have reported high survival damage control Subsequent reports have described both in a of trauma patients (i.e., and in general surgery patients. and the Increases in intra-abdominal pressure may circulation and organ perfusion, the and This can from abdominal trauma by or the use of abdominal return is by compression and of and lower In increased abdominal pressure, associated and a increase in all to diminish cardiac output. blood flow to the liver, and may all be and to the of may also from compression of the can vascular and this from increased abdominal pressure with resultant in and worsens Paradoxically, in this may with of the and of this is the of this but is well described in the surgical 70 packing as a damage control procedure can be a cause of significant abdominal with compression of the to In this setting, a patient should be returned to the operating room for of if of some of the laparotomy to decrease intra-abdominal pressure and to in perfusion, cardiac and In the absence of this packs should be left in place until the patient’s hemodynamic has acidosis has and coagulopathy has been corrected. In this should be accomplished to of the initial packing. may be appropriate if was initially as this may the of a for injury should be is and abdominal closure should be performed if has to this without CONSIDERATIONS The of for rapid abdominal in the trauma patient is made in one from process to In the presence of severe the initially to above the may be In our experience with patients with a access to the can be gained a approach, to and of and bowel from the of the The initial maneuvers on the should be rapid but and are quickly of the abdominal is performed to enable multiple laparotomy packing. This initial packing of the sites of bleeding, from vascular in penetrating injury, or liver in blunt bleeding is less common. this a large abdominal is to abdominal and to all on the surgical bleeding controlled with the packing or during initial exploration, an injury was found and controlled with or this is an time to the to with and source of bleeding has been then a vascular injury is a likely source, and should be by more The bowel is and the are to the and their or the surgical This is important in penetrating pack from the sites of injury, and 19 Control of hemorrhage is the and is accomplished by repair or ligation of vessels. Critical such as the or can be shunted for temporary of can be simple or vascular between tamponade of vascular and viscus injuries has been but in our experience is less applicable. may be necessary for completion of control and temporary for this is high abdominal or or tamponade as a temporary measure to increase blood viscus injury must be controlled as to limit and may be accomplished with or without Occasionally, the injured bowel with or is to contain temporary control of hemorrhage and is obtained, the decision to with definitive repair must be made in with the In the of hypothermia, acidosis, prolonged shock, or coagulopathy, the procedure should be truncated and the patient to the intensive care unit for The presence and of injuries must be when the patient’s physiologic the more injured patient with more severe requires less to be done at this initial are the for damage control packing, and should be to three pressure bleeding, pressure should and should be have as have described the use of or as an between and packing to pack at but have not found these to be necessary. closure of the packed is accomplished by rapid closure the the of abdominal and the and The massive associated with fluid resuscitation and in these patients may even closure impossible. of a or intravenous fluid to has been described as a temporary in this have described to the to preserve the for closure use only the is to or use the for temporary closure. use a modified approach by an surgical over the of the abdominal with its the are above the and the and at the of the An is over the and and to the of the and while the abdominal are toward the The of to the abdominal fluid to the and a to the the has been described as a with the damage control approach, have had such in our this The of are definitive organ repair and complete closure. The should be undertaken when the patient is with correction of hypothermia, acidosis, and may be necessary if is of ongoing hemorrhage than units of packed red blood in the early acidosis, or abdominal massive may limit abdominal closure at but closure has been described in over of of is essential at and access should be the safe use of in an has been this is not our have or in the patient be of our experience that of the abdominal may at closure or of is limited to cases in which is other for of to initially with total and reserve until a can be in the patient. of a damage control may be appropriate for to to for of fluid and at closure. at this the be but the a large is with planned repair to 12 and be a abdominal reconstruction is with the of an closure. to 3 is for of a 6 to 12 this from the and closure can be requiring muscle the physiologic of the patient who requires the damage control approach, it is not that the rate of and mortality is includes intra-abdominal and abdominal organ is described in to of patients, significantly to the mortality rate of to In patients laparotomy for hepatic injury, of have been to to control liver bleeding include ligation of bleeding partial and hepatic tamponade and have also been packing or tamponade is an procedure to control The need for this approach has been reported in to 5% of liver injuries. be the packs must pressure and that are bleeding are not to control by The is injured in abdominal trauma and may present as a source of The patient in with injury requires immediate and at are and 19 Occasionally, the temporary packing to tamponade of vessels until coagulopathy is at the packs are and are at the surgeon’s and injuries to the and are often associated with vascular injury in the patient in mortality is to The should be the and of injury The should then be and Definitive repair is undertaken at and may include or more injury in the exsanguinating patient is with by rapid if a normal is in the of other severe injuries should be packed than to more bleeding and An however, ongoing hemorrhage from an and for In some for hemorrhage or may be more appropriate and than injuries are to reconstruction in the patient both bleeding is and temporary control of can be with can be injury in the patient can also be temporarily with a or Definitive repair can be accomplished at and are to the management of the severely injured patient with can restore of the in fractures, and venous bleeding is with by When laparotomy the of the of is to pack the with gauze to tamponade, the laparotomy, and directly to angiography for to control In our these cases are and closure has been necessary to limit the of and with and temporary at sites more conventional to in the patient in in the can be accomplished with temporary if injury is ligation should be considered as an and may be should be performed in the of In the time and blood should be the way to temporary closure and after physiologic Packing the when severely injured has physiologic and is limited to the and The goal of abbreviated is to bleeding and restore a physiologic state. of the can often rapidly and control of air may be an way to control hemorrhage in penetrating The the is between or with a vessel and control of air This the need for injury can be treated with airway control at the site of injuries, may be but can be to with with an can be repairs are not in the patient in and rapid of the or is injury is treated by and injury to control hemorrhage and maintain flow to repair and are rapid such as and at are time to use in the cold, exsanguinating patient. vascular control tamponade the site has been injury in the is for the patient in Most and can be to the patient’s (Table of the or or external however, often significant damage or This should be for the of situations. must be to lower and laparotomy to An to ligation may be the rapid of temporary or venous and is for time and blood performing reconstruction in the patient in must ligation to The damage control approach can be in operating room by general surgeons. the first of laparotomy or with control of bleeding and contamination, packing, and closure is for where experience with these injuries may be or the necessary for resuscitation may be Once Part is the patient can be to a trauma or with and in the patient management and definitive repair of the injuries. Damage control is of as a lifesaving in patients with exsanguinating trauma and intra-abdominal injuries. The technique can be in a of injury and is appropriate in patients acidosis, hypothermia, and coagulopathy from The resuscitation is at normal physiology and oxygen coagulopathy, hypothermia, and acidosis. of abdominal must be to The and pack is the time to definitive repair and and to place closure with or without must be done with on the and the of the from several up to of patients this approach, the of intra-abdominal and organ are study is to more better for this is also to the of to of resuscitation, better of temporary and to limit intra-abdominal and or blunt organ and The use of procedures and the of the damage control approach of surgical for injuries

cw laser action was achieved on the 2P1/2→2P3/2 transition of the iodine atom by energy transfer from the 1Δ metastable state of O2. The excited oxygen was generated chemically by flowing chlorine gas through a basic solution of 90% H2O2. The effluent from the oxygen generator was mixed with molecular iodine at the entrance of a longitudinal flow laser cavity where the I2 was dissociated by a small amount of O2(1Σ) that was present in the flow due to energy pooling processes. The measured output power was greater than 4 mW.

Covers advancements in spacecraft and tactical and strategic missile systems, including subsystem design and application, mission design and analysis, materials and structures, developments in space sciences, space processing and manufacturing, space operations, and applications of space technologies to other fields.

BACKGROUND: While the use of vascular shunts as a damage control adjunct has been described in series from civilian institutions no contemporary military experience has been reported. The objective of this study is to examine patterns of use and effectiveness of temporary vascular shunts in the contemporary management of wartime vascular injury. MATERIALS: From September 1, 2004 to August 31, 2005, 2,473 combat injuries were treated at the central echelon III surgical facility in Iraq. Vascular injuries were entered into a registry and reviewed. Location of shunts was divided into proximal and distal, and shunt patency, complications and limb viability were examined. RESULTS: There were 126 extremity vascular injuries treated. Fifty-three (42%) had been operated on at forward locations and 30 of 53 (57%) had temporary shunts in place upon arrival to our facility. The patency for shunts in proximal vascular injuries was 86% (n = 22) compared with 12% (n = 8) for distal shunts (p < 0.05). All shunts placed in proximal venous injuries were patent (n = 4). Systemic heparin was not used and there were no shunt complications. All shunted injuries were reconstructed with vein in theater and early viability for extremities in which shunts were used was 92%. CONCLUSIONS: Temporary vascular shunts are common in the management of wartime vascular injury. Shunts in proximal injuries including veins have high patency rates compared with those placed in distal injuries. This vascular adjunct represents a safe and effective damage control technique and is preferable to attempted reconstruction in austere conditions.

A two-person, noncooperative game in which the players move in sequence can be modeled as a bilevel optimization problem. In this paper, we examine the case where each player tries to maximize the individual objective function over a jointly constrained polyhedron. The decision variables are variously partitioned into continuous and discrete sets. The leader goes first, and through his choice may influence but not control the responses available to the follower. For two reasons the resultant problem is extremely difficult to solve, even by complete enumeration. First, it is not possible to obtain tight upper bounds from the natural relaxation; and second, two of the three standard fathoming rules common to branch and bound cannot be applied fully. In light of these limitations, we develop a basic implicit enumeration scheme that finds good feasible solutions within relatively few iterations. A series of heuristics are then proposed in an effort to strike a balance between accuracy and speed. The computational results suggest that some compromise is needed when the problem contains more than a modest number of integer variables.

BACKGROUND: Effective medication is limited for the relief of intermittent claudication, a common manifestation of arterial occlusive disease. Cilostazol is a potent inhibitor of platelet aggregation with vasodilation effects. OBJECTIVE: To evaluate the safety and efficacy of cilostazol for the treatment of intermittent claudication. METHODS: Thirty-seven outpatient vascular medicine clinics at regional tertiary and university hospitals in the United States participated in this multicenter, randomized, double-blind, placebo-controlled, parallel trial. Of the 663 screened volunteer patients with leg discomfort, a total of 516 men and women 40 years or older with a diagnosis of moderately severe chronic, stable, symptomatic intermittent claudication were randomized to receive cilostazol, 100 mg, cilostazol, 50 mg, or placebo twice a day orally for 24 weeks. Outcome measures included pain-free and maximal walking distances via treadmill testing, patient-based quality-of-life measures, global assessments by patient and physician, and cardiovascular morbidity and all-cause mortality survival analysis. RESULTS: The clinical and statistical superiority of active treatment over placebo was evident as early as week 4, with continued improvement at all subsequent time points. After 24 weeks, patients who received cilostazol, 100 mg, twice a day had a 51% geometric mean improvement in maximal walking distance (P<.001 vs placebo); those who received cilostazol, 50 mg, twice a day had a 38% geometric mean improvement in maximal walking distance (P<.001 vs placebo). These percentages translate into an arithmetic mean increase in distance walked, from 129.7 m at baseline to 258.8 m at week 24 for the cilostazol, 100 mg, group, and from 131.5 to 198.8 m for the cilostazol, 50 mg, group. Geometric mean change for pain-free walking distance increased by 59% (P<.001) and 48% (P<.001), respectively, in the cilostazol, 100 mg, and cilostazol, 50 mg, groups. These results were corroborated by the results of subjective quality-of-life assessments, functional status, and global evaluations. Headache, abnormal stool samples or diarrhea, dizziness, and palpitations were the most commonly reported potentially drug-related adverse events and were self-limited. A total of 75 patients (14.5%) withdrew because of any adverse event, which was equally distributed between all 3 treatment groups. Similarly, there were no differences between groups in the incidence of combined cardiovascular morbidity or all-cause mortality. CONCLUSION: Compared with placebo, long-term use of cilostazol, 100 mg or 50 mg, twice a day significantly improves walking distances in patients with intermittent claudication.

In this paper, we report a successful realization and integration of a gold two-dimensional hole array (2DHA) structure with semiconductor InAs quantum dot (QD). We show experimentally that a properly designed 2DHA-QD photodetector can facilitate a strong plasmonic-QD interaction, leading to a 130% absolute enhancement of infrared photoresponse at the plasmonic resonance. Our study indicates two key mechanisms for the performance improvement. One is an optimized 2DHA design that permits an efficient coupling of light from the far-field to a localized plasmonic mode. The other is the close spatial matching of the QD layers to the wave function extent of the plasmonic mode. Furthermore, the processing of our 2DHA is amenable to large scale fabrication and, more importantly, does not degrade the noise current characteristics of the photodetector. We believe that this demonstration would bring the performance of QD-based infrared detectors to a level suitable for emerging surveillance and medical diagnostic applications.

Studies in humans and in experimental models of HIV-1 infection indicate an important role for monocyte chemoattractant protein-1 (MCP-1; also known as CC chemokine ligand 2), a potent chemoattractant and activator of mononuclear phagocytes (MP) in the pathogenesis of HIV-associated dementia (HAD). We determined the influence of genetic variation in MCP-1 on HIV-1 pathogenesis in large cohorts of HIV-1-infected adults and children. In adults, homozygosity for the MCP-1 -2578G allele was associated with a 50% reduction in the risk of acquiring HIV-1. However, once HIV-1 infection was established, this same MCP-1 genotype was associated with accelerated disease progression and a 4.5-fold increased risk of HAD. We examined the molecular and cellular basis for these genotype-phenotype associations and found that the mutant MCP-1 -2578G allele conferred greater transcriptional activity via differential DNA-protein interactions, enhanced protein production in vitro, increased serum MCP-1 levels, as well as MP infiltration into tissues. Thus, MCP-1 expression had a two-edged role in HIV-1 infection: it afforded partial protection from viral infection, but during infection, its proinflammatory properties and ability to up-regulate HIV-1 replication collectively may contribute to accelerated disease progression and increased risk of dementia. Our findings suggest that MCP-1 antagonists may be useful in HIV-1 infection, especially for HAD, and that HIV+ individuals possessing the MCP-1 -2578G allele may benefit from early initiation of antiretroviral drugs that effectively cross the blood-brain barrier. In a broader context, the MCP-1 -2578G allele may serve as a genetic determinant of outcome of other disease states in which MP-mediated tissue injury is central to disease pathogenesis.

We present a dynamic model of thermal modal instability in large mode area fiber amplifiers. This model allows the pump and signal optical intensity distributions to apply a time-varying heat load distribution within the fiber. This influences the temperature distribution that modifies the optical distributions through the thermo-optic effect thus creating a feedback loop that gives rise to time-dependent modal instability. We describe different regimes of operation for a representative fiber design. We find qualitative agreement between simulation results and experimental results obtained with a different fiber including the time-dependent behavior of the instability and the effects of different cooling configurations on the threshold. We describe the physical processes responsible for the onset of the instability and suggest possible mitigation approaches.

Abstract Smithtown is an intelligent tutoring system designed to enhance an individual's scientific inquiry skills as well as to provide an environment for learning principles of basic microeconomics. It was hypothesized that computer instruction on applying effective interrogative skills (e.g., changing one variable at a time while holding all else constant) would ultimately lead to the acquisition of the specific subject matter. This paper presents an evaluation of Smithtown in two studies of individual differences in learning. Experiment 1, an exploratory study, demonstrated that Smithtown fared very well when compared to traditional instruction on economics and delineated the performance indicators which separated better from worse learners in this discovery environment. Experiment 2 extended the findings from the exploratory study using a large sample of subjects (N = 530) from a different population interacting with Smithtown and showed that the performance indicators relating to hypothesis generation and testing were the most predictive of successful learning in Smithtown, accounting for considerably more of the variance in our learning criterion than a measure of general intelligence. Overall, the system performed as expected. Tutoring on scientific inquiry skills resulted in increased knowledge of microeconomics. The differentiating behaviors between more and less successful subjects were in agreement with specific behaviors relating to individual differences found in general studies on problem solving and concept formation. From an instructional perspective, the behaviors we have denoted can serve as a focal point for relevant intervention studies. From a design perspective, findings from these studies suggest modifications to intelligent tutoring systems so they may be more like the individualized teaching systems they have the potential to be. Additional informationNotes on contributorsValerie J. Shute The authors wish to acknowledge the many persons whose contributions have been invaluable to this project: Bill Alley, Jeff Blais, Jeff Bonar, Ray Christal, Kathleen Katterman, Pat Kyllonen, Alan Lesgold, Kalyani Raghavan, Wes Regian, Paul Resnick, and Dan Woltz. A special note of gratitude must be extended to the creative and diligent programmers of Smithtown: Jamie Schultz and Audrey Peterson Support for the large‐scale testing and analyses of Smithtown was provided by the Learning Abilities Measurement Program (LAMP), part of the Air Force Human Resources Laboratory. The Center for the Study of Learning is funded by the Office of Educational Research and Improvement of the U.S. Department of Education. The opinions expressed do not necessarily reflect the position or policy of either AF‐HRL or OERI and no official endorsement should be inferred