While the effects of an invasive alien plant that has become dominant in a community may seem obvious, there are few studies that attempt to understand how impacts vary according to the ...characteristics of invaders and recipient communities. For this purpose, the vegetation of invaded and non-invaded plots was sampled for eight different invasive species in a variety of habitats within the French continental Mediterranean region. Most of the observed impact variation was species-specific, with greater effects on community-level metrics found for Carpobrotus spp. and Reynoutria × bohemica and lower effects for Amorpha fruticosa, Ambrosia artemisiifolia and Phyla filiformis. Some trends were consistent with competition-driven processes, with higher impact found in the presence of rhizomatous and creeping perennial invasive species compared to annuals, or in habitats with sparse vegetation. The importance of community characteristics such as the cover of the invasive plant or the differences in cover between the invader and the native dominant species confirmed previous results obtained in Central Europe. Therefore, such variables, easy to measure and with a generic value, could be profitably integrated into risk assessment methods to improve the prediction of the most threatened habitats. Beyond the overall decline in species diversity, the presence of some invasive species was associated with significant changes in species composition, with a filtering toward more shade-tolerant and nitrophilous ruderal species. Managers should consider replacement of resident species by species with different ecological preferences together with simple community-level metrics, to decide whether management is justified.
Simulators are being used more and more for teaching and testing laparoscopic skills. However, it has yet to be firmly established that simulator performance reflects operative laparoscopic skill. ...The study reported here was designed to test the hypothesis that laparoscopic simulator performance predicts intraoperative laparoscopic skill.
A review of our prospectively maintained database identified 40 subjects who underwent Fundamentals of Lapraoscopic Surgery (FLS) skills testing and objective intraoperative assessments within the same 6-month period. Subjects consisted of 22 novice (postgraduate year PGY 1-2), 10 intermediate (PGY 3-4), and 8 experienced (PGY 5, fellows, and attendings) laparoscopic surgeons. Laparoscopic performance was objectively assessed in the operating room using the previously validated Global Operative Assessment of Laparoscopic Skill (GOALS). Analysis of variance (ANOVA) was used to compare mean FLS scores and mean GOALS scores across experience levels. The relationship between individual FLS scores and GOALS scores was assessed with linear regression analysis. A multivariate analysis evaluated FLS score and surgeon experience as predictors of intraoperative GOALS score. A receiver-operator curve (ROC) was constructed in order to define an FLS cutoff score that predicts intraoperative performance at or above the level of experienced surgeons. Significance was defined as p < 0.05.
Mean FLS scores and mean GOALS scores increased with increasing experience. Individual FLS scores correlated significantly with intraoperative GOALS scores (0.77, p < 0.001). Multivariate analysis confirmed that FLS score is an independent predictor of intraoperative GOALS scores. The ROC identified an FLS cutoff score of 70 with optimal sensitivity (91%) and specificity (86%) for predicting a GOALS score at or above the level of experienced surgeons.
In this study sample, FLS simulator scores were independently predictive of intraoperative laparoscopic performance as measured by GOALS. More precisely, an FLS cutoff score of 70 optimized sensitivity and specificity for expert intraoperative performance. A larger prospective study is justified to validate these findings.
Background
Data are lacking to support the cost‐effectiveness of enhanced recovery pathways (ERP) for oesophagectomy. The aim of this study was to investigate the impact of an ERP on medical costs ...for oesophagectomy.
Methods
This study investigated all patients undergoing elective oesophagectomy between June 2009 and December 2011 at a single high‐volume university hospital. From June 2010, all patients were enrolled in an ERP. Clinical outcomes were recorded for up to 30 days. Deviation‐based cost modelling was used to compare costs between the traditional care and ERP groups.
Results
A total of 106 patients were included (47 traditional care, 59 ERP). There were no differences in patient, pathological and operative characteristics between the groups. Median length of hospital stay (LOS) was lower in the ERP group (8 (interquartile range 7–18) days versus 10 (9–18) days with traditional care; P = 0·019). There was no difference in 30‐day complication rates (59 per cent with ERP versus 62 per cent with traditional care; P = 0·803), and the 30‐day or in‐hospital mortality rate was low (3·8 per cent, 4 of 106). Costs in the on‐course and minor‐deviation groups were significantly lower after implementation of the ERP. The pathway‐dependent cost saving per patient was €1055 and the overall cost saving per patient was €2013. One‐way sensitivity analysis demonstrated that the ERP was cost‐neutral or more costly only at extreme values of ward, operating and intensive care costs.
Conclusion
A multidisciplinary ERP for oesophagectomy was associated with cost savings, with no increase in morbidity or mortality.
More evidence of benefit
Women who carry germ-line mutations in BRCA1/2 are at very high risk of developing breast and ovarian cancer. Breast conserving therapy is associated with a similar risk of ipsilateral cancer ...recurrence in BRCA carriers compared with non-carriers. However, the risk of subsequent contralateral breast cancer in carriers is markedly increased. Therefore, mastectomy of the diseased breast along with risk reducing mastectomy of the contralateral breast is often advocated for BRCA carriers who are treated for early breast cancer. Yet, many BRCA carriers forgo this option for fear of harmful effects and choose breast conserving treatment and observation instead. In Israel, BRCA-associated breast cancer is relatively common. Accordingly, a national protocol was devised for this enriched population.
In this Institutional Review Board-approved phase II trial, the option of prophylactic irradiation to the contralateral breast, in addition to standard loco-regional treatment, was offered to BRCA carrier patients treated for early breast cancer who declined contralateral mastectomy. The primary end point was contralateral breast cancer.
Between May 2007 and October 2017, 162 patients were enrolled. Eighty-one patients opted for standard loco-regional treatment including surgery and radiation to the involved side (control arm) and 81 patients chose additional contralateral breast irradiation (intervention arm). At a median follow-up of 58 months, 10 patients developed contralateral breast cancer in the control arm at a median of 32 months, as compared with 2 patients in the intervention arm who developed contralateral breast cancer 80 and 105 months after bilateral breast irradiation (log-rank P = 0.011).
Among BRCA carrier patients treated for early breast cancer, the addition of contralateral breast irradiation was associated with a significant reduction of subsequent contralateral breast cancers and a delay in their onset.
Phase II, comparative two-arm trial (NCT00496288).
Artificial intelligence (AI) has been a topic of substantial interest for radiologists in recent years. Although many of the first clinical applications were in the neuro, cardiothoracic, and breast ...imaging subspecialties, the number of investigated and real-world applications of body imaging has been increasing, with more than 30 FDA-approved algorithms now available for applications in the abdomen and pelvis. In this manuscript, we explore some of the fundamentals of artificial intelligence and machine learning, review major functions that AI algorithms may perform, introduce current and potential future applications of AI in abdominal imaging, provide a basic understanding of the pathways by which AI algorithms can receive FDA approval, and explore some of the challenges with the implementation of AI in clinical practice.
Summary
Integrating principles of ecological intensification into weed management strategies requires an understanding of the many relationships among weeds, crops and other organisms of ...agro‐ecosystems in a changing context. Extensively used during the last two decades in weed science, trait‐based approaches have provided general insights into weed community response to agricultural practices, and recently to understanding the effect of weeds on agro‐ecosystem functioning. In this review, we provide a holistic synthesis of the current knowledge on weed response and effect functional traits. Based on the literature and recent advances in weed science, we review current knowledge on (i) weed functional groups and ecological strategies, (ii) weed functional response traits to cropping systems and (iii) weed functional effect traits affecting agro‐ecosystem functioning. For each functional trait, we explicitly present the assumptions and evidence on the linkage between trait values and ecological functions, in response to either management practices, for example tillage, sowing and herbicides, or biotic interactions, for example crop–weed competition and pollination. Finally, we address and discuss major research avenues that may significantly improve the use of traits and the knowledge of functional diversity in weed science for the future, especially to design and implement more environmentally sustainable weed management strategies.
Purpose
Practice patterns for inguinal hernia repair vary significantly among surgeons. The purpose of this study was to identify perceived indications for laparoscopic inguinal hernia repair (LIHR), ...and to identify barriers to its adoption and educational needs for surgeons.
Methods
A web-based survey was sent to general surgery members of several North American surgical societies, and to surgical residents through program directors. The 33-item survey was divided in 4 sections: demographics, utilization of techniques, management based on 11 clinical scenarios, reasons for not performing LIHR and educational needs for those who want to learn.
Results
Six hundred and ninety-seven general surgeons and 206 general surgery residents responded to the survey. Surgeons with MIS fellowships, and surgeons at the beginning of their careers are more likely to perform LIHR. Out of the 11 clinical scenarios, surgeons preferred a laparoscopic approach (totally extraperitoneal or transabdominal preperitoneal) for bilateral (48 %) and recurrent (44 %) hernias. However, 46 % of respondents never perform LIHR. Of these, 70 % consider the benefits of laparoscopy to be minimal, 59 % said they lack the requisite training, and 26 % are interested in learning. Surgeons (70 %) and residents (73 %) agreed that the best educational method would be a course followed by expert proctoring.
Conclusion
Surgeons remain divided on the utility of laparoscopic surgery for inguinal hernia repair. Nearly half of responding surgeons never perform LIHR, and the other half offer it selectively. One quarter of surgeons who do not perform LIHR are interested in learning. This reveals a knowledge gap that could be addressed with educational programs.
Biodiversity impacts ecosystem properties and the ecosystem services provided by those ecosystems. As a result, promoting plant diversity in agricultural systems has been a key issue in agriculture ...over recent years. In this context, weeds have an important role in maintaining field biodiversity, when it is balanced with their potential negative impact on crop production. Functional trait diversity, rather than the diversity of species per se, is a facet of biodiversity most directly related to species and community responses to management practices, with subsequent consequences for ecosystem services. Trait-based approaches, originally developed in the field of comparative ecology, allowed the description of weed species responses to management practices in annual crop systems. Here, we aimed to extend the trait-based approach to the spontaneous vegetation of vineyards. First, we propose a brief summary of current knowledge about weed communities in vineyards. Then we show how the relationships between management practices, weeds and grape vines can be translated into a response-effect framework: soil management practices (tillage, cover crops, spontaneous vegetation) can be considered as environmental filters that determine the composition and structure of vegetation, which, in turn, modify grapevine growth conditions in the vineyard. Finally, we tested this framework in a Mediterranean vineyard where, for 2 years, we characterized the responses of different components of weed communities (taxonomic and functional composition) in three inter-row management practices (tillage, cover crops and mowing spontaneous vegetation) and their effects on several grapevine processes (vine yield, vine leaf water potential and assimilable nitrogen in must).
Background
While operating, surgeons are required to make cognitive decisions and often are interrupted to attend to questions from other members of the health care team. Technical automatization may ...be achieved by experienced surgeons such that these distractions have little effect on performance of either the surgical or the cognitive task. This study assessed the effect of adding a distracting cognitive task on performance of a basic laparoscopic skill by novice and experienced surgeons.
Methods
In this study, 31 novice (medical students in postgraduate years PGYs 1–2) and 9 experienced (fellows/attendants and PGYs 4–5) laparoscopic surgeons practiced the Fundamentals of Laparoscopic Surgery (FLS) laparoscopic peg transfer task until their scores stabilized. The mean normalized score after five repetitions then was recorded. The subjects also were tested on the number of mathematical addition questions they could answer in 1 min. This was repeated five times, with the mean number of questions attempted and the accuracy (% correct) recorded. The laparoscopic and addition tasks then were performed concurrently five times. Data, presented as mean ± standard deviation, were analyzed using Student’s
t
-test. A
p
value less than 0.05 was considered statistically significant.
Results
After practice to stable peg transfer performance, the baseline peg transfer score was higher in the experienced group (98 ± 6 vs 87 ± 12;
p
< 0.01). There were no baseline differences between the groups in the number of math questions attempted in 1 min (10 ± 2 vs 9 ± 2;
p
= 0.55) or the number of correct answers (9 ± 3 vs 8 ± 3;
p
= 0.36). The comparison of baseline performance and dual-task performance showed that the experienced surgeons had no decline in peg transfer score (98 ± 6 vs 97 ± 6;
p
= 0.48), number of questions attempted in 1 min (10 ± 2 vs 9 ± 3;
p
= 0.32), or number of correct answers (9 ± 3 vs 8 ± 3;
p
= 0.46). In contrast, dual-tasking among the novices was associated with a decrease in the number of questions attempted (9 ± 2 vs 8 ± 2;
p
< 0.01) and the number of correct answers (8 ± 3 vs 7 ± 2;
p
= 0.02), and with no change in the peg transfer score (87 ± 12 vs 88 ± 8;
p
= 0.38) compared with baseline.
Conclusions
Distraction significantly decreased a novice’s ability to process cognitively based math problems, whereas there was no effect on experienced subjects. This occurred despite the fact that the novice group had practiced to high-level peg transfer scores at baseline. This suggests that the experienced surgeons had achieved automatization of the peg transfer basic surgical skill to a level that cognitive distraction did not affect performance of either task. The experienced surgeons were able to attend equally to both tasks, whereas the novices attended to the surgical task at the expense of some aspects of cognitive task performance.
Introduction
Achieving proficiency in flexible endoscopy is a major priority for general surgery training programs. The Fundamentals of Endoscopic Surgery (FES™) is a high-stakes examination of the ...knowledge and skills required to perform flexible endoscopy. The objective of this study was to establish additional evidence for the validity of the FES™ hands-on test as a measure of flexible endoscopy skills by correlating clinical colonoscopy performance with FES™ score.
Methods
Participants included FES™-naïve general surgery residents, gastroenterology fellows at all levels of training and attending physicians who regularly perform colonoscopy. Each participant completed a live colonoscopy and the FES™ hands-on test within 2 weeks. Performance on live colonoscopy was measured using the Global Assessment of Gastrointestinal Endoscopic Skills—Colonoscopy (GAGES-C, maximum score 20), and performance on the FES™ hands-on test was assessed by the simulator’s computerized scoring system. The clinical assessor was blinded to simulator performance. Scores were compared using Pearson’s correlation coefficient.
Results
A total of 24 participants were enrolled (mean age 30; 54 % male) with a broad range of endoscopy experience; 17 % reported no experience, 54 % had <25 previous colonoscopies; and 21 % had >100. The FES™ and GAGES scores reflected the broad range of endoscopy experience of the study group (FES™ score range 32–105; GAGES score range 5–20). Pearson’s correlation coefficient between GAGES-C scores and FES™ hands-on test scores was 0.78 (0.54–0.90,
p
< 0.0001). All eight participants with GAGES-C score >15/20 achieved a passing score on the FES™ hands-on test.
Conclusion
There is a strong correlation between clinical colonoscopy performance and scores achieved on the FES™ hands-on test. These data support the validity of FES™ as a measure of colonoscopy skills.
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