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:The objective of this study was to develop and test an integrated conceptual model of microcomputer usage. This study used the technology acceptance model and sought to extend it by investigating the impact of the external factors (i.e., individual, organizational, and system characteristics) on the user acceptance of microcomputer technology. The paper reports the results of a field study investigating the determinants of microcomputer usage. The analyses of the measurement model confrrm the existence of two distinct constructs of (1) beliefs—perceived usefulness and perceived ease of use; (2) organizational support—management support and end-user computing (EUC) support; and (3) microcomputer usage—perceived usage and variety of use. The tested conceptual model confrrms the effects of individual, organizational, and system characteristics on perceived ease of use and perceived usefulness. The model also confirms the influence of perceived ease of use on perceived usefulness, and the effects of perceived usefulness on perceived usage and variety of use. Results confrrm several previously proposed notions, including the effects of individual, organizational, and system characteristics on ease of use and usefulness; the influence of ease of use on usefulness, and the effects of perceived usefulness on usage and variety of use. The results demonstrate the utility of investigating factors contributing to microcomputer usage and the external factors affecting endogenous variables such as system usefulness. The importance of EUC support and management support is corroborated, as well as the need for designing mechanisms such as training programs and newsletters to improve user perceptions of microcomputers.

Although the significance of various prognostic factors, such as tumor size and mitotic index (MI), has been well established for smooth-muscle tumors of the stomach, the significance of these factors in other sites is less well defined. We studied 1004 patients with gastrointestinal smooth-muscle tumors for whom vital status could be determined. The average MI and tumor size varied significantly among the five major sites examined: esophagus (53 cases), stomach (524 cases), small bowel 252 cases), colon/rectum (108 cases), and omentum/mesentery/peritoneum (67 cases). There was a significant difference in site-specific survival (p = 0.001), with 10-year survival varying between 50% and 70%. Multivariate analysis demonstrated tumor location (p = 0.0320), size (p = 0.0003), MI (p < 0.0001), and patient age (p < 0.0001) to each carry independent prognostic value. The significance of MI was highly site dependent. Separation of survival curves for the stomach, using a threshold for analysis of either 5 or 10 mitotic figures/50 high-power fields, was very good. In contrast, small-bowel tumors showed little separation between survival curves, regardless of whether a threshold of 1, 5, or 10 mitotic figures MF/50 high-power fields was used to distinguish groups. In no site were tumor size and MI alone sufficient to provide an accurate long-term prediction of prognosis. Although tumor location, size, MI, and age have independent value in predicting the prognosis of patients with gastrointestinal smooth-muscle tumors, better methods are still required to accurately predict clinical course.

The military drawdown program of the early 1990's provides an opportunity to obtain estimates of personal discount rates based on large numbers of people making real choices involving large sums. The program offered over 65,000 separatees the choice between an annuity and a lump-sum payment. Despite break-even discount rates exceeding 17 percent, most of the separatees selected the lump sum—saving taxpayers $1.7 billion in separation costs. Estimates of discount rates range from 0 to over 30 percent and vary with education, age, race, sex, number of dependents, ability test score, and the size of payment. (JEL D91)

This article examines the incentives of contractual parties to design agreements that are left intentionally incomplete with regard to future duties or contingencies. More complete contracts mitigate ex post opportunism and the associated distortions in unobservable investment, but at the cost of additional resources expended in ex ante design. The optimal degree of contractual incompleteness involves a tradeoff between these opposing forces, the magnitudes of which may be predicted based on observable characteristics of the transactors and of the exchange environment. The resulting hypotheses are tested using panel data on the pricing procedures using in Air Force engine procurement contracts. We conclude that the degree of contractual completeness chosen in practice reflects a desire by the parties to minimize the economic costs associated with contractual exchange.

JOSEPH S. NYE, JR., Sultan of Oman Professor of International Relations, is Dean of the John F. Kennedy School of Government. Nye has been on the faculty at Harvard since 1964, during which time he also served as Assistant Secretary of Defense for International Security Affairs, Chair of the National Intelligence Council, and Deputy Assistant Secretary of State for Security Assistance, Science and Technology. He is the author of numerous books and articles on national security policy.

OBJECTIVE: The authors present an accurate and comprehensive snapshot of appendicitis and the practice of appendectomy in the 1990s. METHODS: Appendectomies were performed on 4950 patients in 147 Department of Defense hospitals worldwide over a 12-month period ending January 31, 1993. RESULTS: The median age was 23 years (range, 6 months to 82 years) with 64% males and 36% females. The patients were assigned a diagnosis of normal appendix in 632 (13%) cases, acute appendicitis in 3286 (66%) cases, and perforated appendicitis in 1032 (21%) cases. There were no differences in perforation and normal appendix rates between those operations performed in teaching hospitals versus community hospitals or between high-volume hospitals (> or = 100 appendectomies/year) versus low-volume hospitals. Both a preoperative temperature > or = 100.5 and a preoperative leukocyte count > or = 10,000 were incapable of discriminating between patients with appendicitis and those with a normal appendix. Multivariate analysis showed a significantly increased risk of perforation associated with age younger than or equal to 8 years (38% vs. 18%) and age older than or equal to 45 years (49% vs. 18%). Females had a significantly higher rate of normal appendices (19% vs. 9%) and a lower rate of perforation (18% vs. 23%). The complication rates to include reoperation and intraabdominal sepsis were markedly increased in those patients with perforation. There were four deaths in this series (0.08%). CONCLUSIONS: Despite a marked decline in associated mortality over the past 50 years, rates of perforation and negative appendectomy remain unchanged because they are influenced strongly by factors untouched by the intervening technologic advances.

Teamwork is integral to a working environment conducive to patient safety and care. Team training is one methodology designed to equip team members with the competencies necessary for optimizing teamwork. There is evidence of team training's effectiveness in highly complex and dynamic work environments, such as aviation and health care. However, most quantitative evaluations of training do not offer any insight into the actual reasons why, how, and when team training is effective. To address this gap in understanding, and to provide guidance for members of the health care community interested in implementing team training programs, this article presents both quantitative results and a specific qualitative review and content analysis of team training implemented in health care. Based on this review, we offer eight evidence-based principles for effective planning, implementation, and evaluation of team training programs specific to health care.

The term, technological forecasting, is appearing with ever increasing frequency in the public utterances of government and industrial leaders. Yet it is obvious to even the most casual observer that little agreement exists as to the meaning of the term, the potential for useful forecasting, regardless of detailed nature, or the status of relevant studies. The purpose of this paper is to review generally the various, apparently useful forecasting techniques, to offer a rationale basis for undertaking a technological forecast, and to place technological forecasting in perspective with regard to other planning inputs.

This paper is the first in a series of articles introducing a new conceptual and methodological framework for the use of experts in decision situations. Presented is the first theory of expert resolution wholly consistent with the Bayesian or subjectivist view of probability. The approach taken rests philosophically on the foundations of decision analysis. The results form practical tools for solving expert resolution problems. The present paper develops a structure in which the expert resolution problem may be logically formulated and conceptually solved. A framework is developed which enables a decision maker to encode his state of information concerning an expert. Application of the tools of Bayesian inference provides a mechanism by which a decision maker can incorporate an expert's opinion into his own. The more complicated case in which a decision maker is confronted with the diverse judgments of more than one expert is also addressed in detail. Additionally, the problem of determining the economic worth of one or a panel of experts is presented.

BACKGROUND: A majority of the nearly 2 million Americans living with limb loss suffer from chronic pain in the form of neuroma-related residual limb and phantom limb pain (PLP). Targeted muscle reinnervation (TMR) surgically transfers amputated nerves to nearby motor nerves for prevention of neuroma. The objective of this study was to determine whether TMR at the time of major limb amputation decreases the incidence and severity of PLP and residual limb pain. STUDY DESIGN: A multi-institutional cohort study was conducted between 2012 and 2018. Fifty-one patients undergoing major limb amputation with immediate TMR were compared with 438 unselected major limb amputees. Primary outcomes included an 11-point Numerical Rating Scale (NRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) pain intensity, behavior, and interference. RESULTS: Patients who underwent TMR had less PLP and residual limb pain compared with untreated amputee controls, across all subgroups and by all measures. Median "worst pain in the past 24 hours" for the TMR cohort was 1 out of 10 compared to 5 (PLP) and 4 (residual) out of 10 in the control population (p = 0.003 and p < 0.001, respectively). Median PROMIS t-scores were lower in TMR patients for both PLP (pain intensity [36.3 vs 48.3], pain behavior [50.1 vs 56.6], and pain interference [40.7 vs 55.8]) and residual limb pain (pain intensity [30.7 vs 46.8], pain behavior [36.7 vs 57.3], and pain interference [40.7 vs 57.3]). Targeted muscle reinnervation was associated with 3.03 (PLP) and 3.92 (residual) times higher odds of decreasing pain severity compared with general amputee participants. CONCLUSIONS: Preemptive surgical intervention of amputated nerves with TMR at the time of limb loss should be strongly considered to reduce pathologic phantom limb pain and symptomatic neuroma-related residual limb pain.

The US Department of Defense has begun to recognize the need to manage and engineer ensembles of systems to address use capability needs. As DoD systems of systems are being recognized with explicit management, systems engineering and funding support, systems engineers face challenges in applying systems engineering processes to support SoS, particularly in the typical situation when the systems retain their independence. This paper describes the situation in SoS in the context of existing SoS frameworks and discusses the current DoD approach to SoS and challenges the SoS environment poses for the systems engineer at both the SoS and system levels. Finally, the paper will suggest some areas for further investigation to address key issues as systems engineering takes up the challenge of these changes in the interdependent networked environment of the future battle space.

The extent of blockade when four different techniques were used for blocking the lumbar plexus was prospectively evaluated in 80 adult patients. The extent of blockade was measured by testing motor function of all nerves except the lateral and posterior femoral cutaneous nerves, which were evaluated by pinprick response. The posterior approaches of Dekrey at L3 (n = 20) and Chayen at L4-5 (n = 20) proved similarly effective in producing blockade of the femoral, obturator, and lateral femoral cutaneous nerves, as well as the nerves to the psoas muscle. The anterior approach of Winnie (femoral sheath or 3-in-1 block) using paresthesia (n = 20) or peripheral nerve stimulation (n = 20) proved effective in producing blockade of the femoral and lateral femoral cutaneous nerves, but ineffective for obturator nerve blockade. None of the four techniques produced blockade of the sacral plexus. Perhaps our means of assessing blockade (motor) is what produced the difference between our findings and those of others.

Studies of posttraumatic stress disorder (PTSD) prevalence associated with deployment to Iraq or Afghanistan report wide variability, making interpretation and projection for research and public health purposes difficult. This article placed this literature within a military context. Studies were categorized according to deployment time-frame, screening case definition, and study group (operational infantry units exposed to direct combat versus population samples with a high proportion of support personnel). Precision weighted averages were calculated using a fixed-effects meta-analysis. Using a specific case definition, the weighted postdeployment PTSD prevalence was 5.5% (95% CI, 5.4-5.6) in population samples and 13.2% (12.8-13.7) in operational infantry units. Both population-level and unit-specific studies provided valuable and unique information for public health purposes; understanding the military context is essential for interpreting prevalence studies.

The processing problems associated with boron carbide and the limitations of its mechanical properties can be significantly reduced when a metal phase (e.g., aluminum) is added. Lower densification temperatures and higher fracture toughness will result. Based on fundamental capillarity ther modynamics, reaction thermodynamics, and densification kinetics, we have established reliable criteria for fabricating B 4 C–Al particulate composites. Because chemical reactions cannot be eliminated, it is necessary to process B 4 C–AI by rapidly heating to near 1200°C (to ensure wetting) and subsequently heat‐treating below 1200°C (for microstructural development).

This article uses three interrelated concepts-ideal type, model, and paradigm-to examine and explain both change and continuity in the American military culture as it undergoes major social change. Briefly, the analysis defines the three concepts and then applies each to current military culture. From this analysis, one sees continuity in the military's cultural paradigm, termed the "combat, masculine-warrior." However, one also sees change as illustrated by the military's "evolving" model of culture. Also discussed is how the military's combat, masculine-warrior paradigm conflicts with its evolving model of culture. This conflict helps explain some of the current turmoil as the military adapts to social change (e.g., diversity). The article concludes with a discussion of a potential paradigm shift in military culture. Hopefully this article provides a framework of analysis from which military leaders can better understand and proactively manage culture and change.

The Long-read RNA-Seq Genome Annotation Assessment Project Consortium was formed to evaluate the effectiveness of long-read approaches for transcriptome analysis. Using different protocols and sequencing platforms, the consortium generated over 427 million long-read sequences from complementary DNA and direct RNA datasets, encompassing human, mouse and manatee species. Developers utilized these data to address challenges in transcript isoform detection, quantification and de novo transcript detection. The study revealed that libraries with longer, more accurate sequences produce more accurate transcripts than those with increased read depth, whereas greater read depth improved quantification accuracy. In well-annotated genomes, tools based on reference sequences demonstrated the best performance. Incorporating additional orthogonal data and replicate samples is advised when aiming to detect rare and novel transcripts or using reference-free approaches. This collaborative study offers a benchmark for current practices and provides direction for future method development in transcriptome analysis.

OBJECTIVE: This study provides the first objective assessment of a complete patient population undergoing laparoscopic cholecystectomy in the steady state. The authors determined the frequency of complications, particularly bile duct, bowel, vascular injuries, and deaths. SUMMARY BACKGROUND DATA: This retrospective study, conducted for the Department of Defense healthcare system by the Civilian External Peer Review Program, is the second complete audit of laparoscopic cholecystectomy. Data were collected on 9130 patients undergoing laparoscopic cholecystectomy between January 1993 and May 1994. METHODS: The study sample consisted of clinical data abstracted from the complete records of 9054 (99.2%) of the 9130 laparoscopic cholecystectomies performed at 94 military medical treatment facilities. RESULTS: Of 10,458 cholecystectomies performed in the Military Health Services System, 9130 (87.3%) were laparoscopic and 1328 (12.7%) were traditional open procedures. Seventy-six medical records were incomplete: however, there was sufficient data to determine mortality and bile duct injury rates. Of the remaining 9054 cases, 6.09% experienced complications, including bile duct (0.41%), bowel (0.32%), and vascular injuries (0.10 percent). The mortality rate was 0.13%. Access via Veress technique was used in 57.6% and Hasson technique in 42.4% of patients. Intraoperative cholangiograms were performed in 42.7% of the cases with a success rate of 86.2%. Eight hundred ninety-two (9.8%) patients were converted to open cholecystectomies. CONCLUSIONS: In the steady state, despite an increase in the percentage of laparoscopic cholecystectomies performed for nonmalignant gallbladder disease, there continues to be minimal complications and low mortality.

Team performance measurement is a critical and frequently overlooked component of an effective simulation-based training system designed to build teamwork competencies. Quality team performance measurement is essential for systematically diagnosing team performance and subsequently making decisions concerning feedback and remediation. However, the complexities of team performance pose a challenge to effectively measuring team performance. This article synthesizes the scientific literature on this topic and provides a set of best practices for designing and implementing team performance measurement systems in simulation-based training.

Carcinosarcoma is a malignant tumor having a mixture of carcinoma and sarcoma containing differentiated mesenchymal elements, such as malignant cartilage, bone, and skeletal muscle. These tumors have been linked histogenetically to pleomorphic carcinomas; it is unclear whether their clinical behavior is significantly different. To investigate this issue, we studied 66 cases of carcinosarcomas of the lung and compared them with cases from a previously published series of pleomorphic carcinomas. Carcinosarcomas show a male-to-female ratio of 7.25:1, with a mean and median age of 65 years. They most often present as solitary masses in the upper lobes and average 7 cm in diameter. Most (62%) were endobronchial or central tumors, whereas 38% were described as peripheral. The most frequent epithelial component was squamous cell carcinoma (46%), followed by adenocarcinoma (31%) and adenosquamous carcinoma (19%), whereas sarcomatous elements most frequently included rhabdomyosarcoma, chondrosarcoma, osteosarcoma, or combinations of these elements. Survival of patients with carcinosarcomas of lung was poor, with a 5-year survival rate of 21.3%. Of several clinical and pathologic parameters, only increased tumor size (with 6 cm as the optimal cutoff point) appeared to be related to reduced survival (p = 0.0195). In comparison with patients with pleomorphic carcinoma, patients with carcinosarcomas had no significant difference in the size of their tumors (p = 1.0), stage at presentation (p = 0.883), location in the lung (p = 0.073), or their overall survival (21.3% vs 15.0%) (p = 0.1038). A significantly greater proportion of patients with carcinosarcoma had squamous cell (p = 0.004) or adenosquamous (p = 0.016) carcinoma, whereas patients who had pleomorphic carcinoma showed a significantly greater frequency of adenocarcinoma (p = 0.029) and large cell carcinoma. The histologic differences between these two types of tumor suggest that they may be different entities with similar behavior, but additional studies are warranted to investigate this hypothesis.

Parkinson's disease (PD), a common disease of the elderly, is a movement disorder characterized by tremor, akinesia, and loss of postural reflexes, leading to immobility and frequent falls. It results from selective loss (death) of dopaminergic neurons in the substantia nigra region of the brain, largely developed prior to clinical diagnosis, and continuous after diagnosis, despite use of current therapeutic modalities. In PD in the United States the cause and mechanism of continued neuron cell death in the substantia nigra is currently unknown. We hypothesize, based upon several lines of evidence, that documented chronically inadequate vitamin D intake in the United States, particularly in the northern states and particularly in the elderly, is a significant factor in the pathogenesis of PD. This hypothesis implies that dietary aid for prevention and therapy for PD is possible.