32 research outputs found

    A Survey of Systems Engineering Effectiveness - Initial Results

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    This survey quantifies the relationship between the application of Systems Engineering (SE) best practices to projects and programs, and the performance of those projects and programs. The survey population consisted of projects and programs executed by defense contractors who are members of the Systems Engineering Division (SED) of the National Defense Industrial Association (NDIA). The deployment of SE practices on a project or program was measured through the availability and characteristics of specific SE-related work products. Project Performance was measured through typically available project measures of cost performance, schedule performance, and scope performance. Additional project and program information such as project size, project domain, and other data was also collected to aid in characterizing the respondent's project. Analysis of the survey responses revealed moderately strong statistical relationships between Project Performance and several categorizations of specific of SE best practices. Notably stronger relationships are apparent by combining the effects of more than one the best practices categories. Of course, Systems Engineering Capability alone does not ensure outstanding Project Performance. The survey results show notable differences in the relationship between SE best practices and performance between more challenging as compared to less challenging projects. The statistical relationship between Project Performance and the combination of SE Capability and Project Challenge is quite strong for survey data of this type

    Computed tomography assessment of postoperative gastric vascular supply and staple-line leak development after sleeve gastrectomy

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    Background: Residual arterial supply of the gastric tube after sleeve gastrectomy (SG) can be damaged by surgery, which can reduce gastric tube perfusion and could promote postoperative leakage. Objective: To compare the postoperative vascularization of the gastric tube using early computed tomography (CT) scanning after SG in patients with or without postoperative staple-line leak. Setting: University hospital. Methods: A retrospective analysis of a prospective database was performed in consecutive patients undergoing SG. Patients who presented with a staple-line leak were matched (1:3) with a control group of patients who underwent surgery without postoperative morbidity during the same period. Gastric tube vascularization was studied on a postoperative day 2 CT scan in both groups of patients. Results: During the study period, 1826 patients underwent SG, including 42 patients (2.3%) who presented with a staple-line leak. Those 42 patients were successfully matched to 126 control patients. Global identification of residual gastric arterial supply in early postoperative CT scans was similar in patients with or without staple-line leak after SG. However, residual vascular supply of the gastroesophageal junction (i.e., terminal and anterior cardiotuberosity branches of the left gastric artery or left inferior phrenic artery) was more frequently interrupted by the staple line in the group of patients who developed a gastric leak. Conclusion: This study suggests a correlation between interruption of the main arteries supplying the gastroesophageal junction by the staple line on early postoperative CT scans and the development of gastric leak after SG. These results support the vascular theory as one of the causes of leak after SG

    Operative management of acute abdomen after bariatric surgery in the emergency setting: the OBA guidelines

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    Background: Patients presenting with acute abdominal pain that occurs after months or years following bariatric surgery may present for assessment and management in the local emergency units. Due to the large variety of surgical bariatric techniques, emergency surgeons have to be aware of the main functional outcomes and long-term surgical complications following the most performed bariatric surgical procedures. The purpose of these evidence-based guidelines is to present a consensus position from members of the WSES in collaboration with IFSO bariatric experienced surgeons, on the management of acute abdomen after bariatric surgery focusing on long-term complications in patients who have undergone laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass. Method: A working group of experienced general, acute care, and bariatric surgeons was created to carry out a systematic review of the literature following the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) and to answer the PICO questions formulated after the Operative management in bariatric acute abdomen survey. The literature search was limited to late/long-term complications following laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass. Conclusions: The acute abdomen after bariatric surgery is a common cause of admission in emergency departments. Knowledge of the most common late/long-term complications (> 4 weeks after surgical procedure) following sleeve gastrectomy and Roux-en-Y gastric bypass and their anatomy leads to a focused management in the emergency setting with good outcomes and decreased morbidity and mortality rates. A close collaboration between emergency surgeons, radiologists, endoscopists, and anesthesiologists is mandatory in the management of this group of patients in the emergency setting

    Structural analysis of the factors pertaining to attitudes toward and consciousness of organ donation : Comparison between Japanese and Americans

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    The purpose of this study is to analyze the background factors relating to opinions on organ donation through factorial and structural comparisons between Japanese and Americans. The data were obtained from responses to a questionnaire (371 Japanese and 41 Americans). The main findings are as follows: 1. Most of the factors, ‘a will for organ donation depending on a recipient’, ‘view of remains’, ‘understanding of brain death’ and so on showed significant differences between Japanese and Americans. 2. Japanese had a better understanding of brain death. On the other hand, the ratio of Americans who were willing to donate an organ was higher than that of Japanese. 3. It was revealed that “the approval of organ donation for the third person, not only for one's family” had an impact for having donor card showing the approval for organ donation. Furthermore, as underlying factors generating differences on organ transplant opinions, differences were found among Japanese between “approval of organ transplant” and the attitude assuming that oneself or a member of one's family was the person concerned with organ transplantation. There were also differences between Japanese and Americans on ideas about a view for life and death such as soul existence or view of remains. The argument for transplantation in Japan should consider these structural differences

    Seagrass Impact on Sediment Exchange Between Tidal Flats and Salt Marsh, and The Sediment Budget of Shallow Bays

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    Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 45 (2018): 4933-4943, doi:10.1029/2018GL078056.Seagrasses are marine flowering plants that strongly impact their physical and biological surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience and sediment transport dynamics is understudied. Here we use six historical maps of seagrass distribution in Barnegat Bay, USA, to investigate the role of these vegetated surfaces on the sediment storage capacity of shallow bays. Analyses are carried out by means of the Coupled‐Ocean‐Atmosphere‐Wave‐Sediment Transport (COAWST) numerical modeling framework. Results show that a decline in the extent of seagrass meadows reduces the sediment mass potentially stored within bay systems. The presence of seagrass reduces shear stress values across the entire bay, including unvegetated areas, and promotes sediment deposition on tidal flats. On the other hand, the presence of seagrasses decreases suspended sediment concentrations, which in turn reduces the delivery of sediment to marsh platforms. Results highlight the relevance of seagrasses for the long‐term survival of coastal ecosystems, and the complex dynamics regulating the interaction between subtidal and intertidal landscapes.2018-10-3
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