On the duality between interaction responses and mutual positions in flocking and schooling.

Recent research in animal behaviour has contributed to determine how alignment, turning responses, and changes of speed mediate flocking and schooling interactions in different animal species. Here, we propose a complementary approach to the analysis of flocking phenomena, based on the idea that animals occupy preferential, anysotropic positions with respect to their neighbours, and devote a large amount of their interaction responses to maintaining their mutual positions. We test our approach by deriving the apparent alignment and attraction responses from simulated trajectories of animals moving side by side, or one in front of the other. We show that the anisotropic positioning of individuals, in combination with noise, is sufficient to reproduce several aspects of the movement responses observed in real animal groups. This anisotropy at the level of interactions should be considered explicitly in future models of flocking and schooling. By making a distinction between interaction responses involved in maintaining a preferred flock configuration, and interaction responses directed at changing it, our work provides a frame to discriminate movement interactions that signal directional conflict from interactions underlying consensual group motion

A standard protocol for describing the evaluation of ecological models

Numerical models of ecological systems are increasingly used to address complex environmental and resource management questions. One challenge for scientists, managers, and stakeholders is to appraise how well suited these models are to answer questions of scientific or societal relevance, that is, to perform, communicate, or access transparent evaluations of ecological models. While there have been substantial developments to support standardised descriptions of ecological models, less has been done to standardise and to report model evaluation practices. We present here a general protocol designed to guide the reporting of model evaluation. The protocol is organised in three major parts: the objective(s) of the modelling application, the ecological patterns of relevance and the evaluation methodology proper, and is termed the OPE (objectives, patterns, evaluation) protocol. We present the 25 questions of the OPE protocol which address the many aspects of the evaluation process and then apply them to six case studies based on a diversity of ecological models. In addition to standardising and increasing the transparency of the model evaluation process, we find that going through the OPE protocol helps modellers to think more deeply about the evaluation of their models. From this last point, we suggest that it would be highly beneficial for modellers to consider the OPE early in the modelling process, in addition to using it as a reporting tool and as a reviewing tool.publishedVersio

Changes in the multidisciplinary management of rectal cancer from 2009 to 2015 and associated improvements in short‐term outcomes

Aim: Significant recent changes in management of locally advanced rectal cancer include preoperative staging, use of extended neoadjuvant therapies, and minimally invasive surgery (MIS). This study was aimed at characterizing those changes and associated short‐term outcomes. Method: We retrospectively analysed treatment and outcome data from patients with T3/4 or N+ locally advanced rectal cancer ≤15 cm from the anal verge who were evaluated at a comprehensive cancer center in 2009–2015. Results: In total, 798 patients were identified and grouped into five cohorts based on treatment year: 2009‐2010, 2011, 2012, 2013, and 2014‐2015. Temporal changes included increased reliance on MRI staging, from 57% in 2009‐2010 to 98% in 2014‐2015 (p < 0.001); increased use of total neoadjuvant therapy, from 17% to 76% (p < 0.001); and increased use of MIS, from 33% to 70% (p < 0.001). Concurrently, median hospital stay decreased (from 7 to 5 days; p < 0.001), as did the rates of grade III‐V complications (from 13% to 7%; p < 0.05), surgical site infections (from 24% to 8%; p < 0.001), anastomotic leak (from 11% to 3%; p < 0.05), and positive circumferential resection margin (from 9% to 4%; p < 0.05). TNM downstaging increased from 62% to 74% (p = 0.002). Conclusion: Shifts toward MRI‐based staging, total neoadjuvant therapy, and MIS occurred between 2009 and 2015. Over the same period, treatment responses improved, and lengths of stay and the incidence of complications decreased

Perianal pyoderma gangrenosum after excision and fulguration of anal condyloma acuminatum

Introduction: Pyoderma gangrenosum (PG) is a rare, inflammatory skin pathology frequently associated with systemic inflammatory disease. While rare after surgery, recognition of this disease in the post-surgical setting is important as it can mimic wound infection. Presentation of case: We herein present a dramatic presentation of perianal PG four days after routine excision and fulguration of anal condyloma acuminatum. The affected area did not improve with broad spectrum antibiotics or surgical debridement. A diagnosis of PG was made from clinical suspicion and pathology findings, and further confirmed with rapid improvement after starting steroids. Diagnosis of this disease in the postoperative period requires high suspicion when the characteristic ulcerative or bullae lesions are seen diffusely and show minimal improvement with antibiotic treatment or debridement. Discussion: Our case highlights the importance of recognizing this disease in the post-operative period, to allow for early initiation of appropriate treatment and prevent unnecessary surgical debridement of a highly sensitive area. There have been 32 case reports of PG in the colorectal literature, mostly following stoma creation. There is one case report of idiopathic perianal pyoderma gangrenosum with no known prior trauma. To our knowledge there are no previously reported cases of perianal PG after routine elective anorectal surgery. Conclusion: This is the first reported case of perianal pyoderma gangrenosum in the post-surgical setting. Increased awareness of pyoderma gangrenosum in the surgical literature will aid in prompt diagnosis and proper medical management of this uncommon postoperative morbidity

Biologically inspired herding of animal groups by robots

1. A single sheepdog can bring together and manoeuvre hundreds of sheep from one location to another. Engineers and ecologists are fascinated by this sheepdog herding because of the potential it provides for 'bioherding': a biologically inspired herding of animal groups by robots. Although many herding algorithms have been proposed, most are studied via simulation. 2. There are a variety of ecological problems where management of wild animal groups is currently impossible, dangerous, and/or costly for humans to manage directly, and which may benefit from bioherding solutions. 3. Unmanned aerial vehicles (UAVs) now deliver significant benefits to the economy and society. Here, we suggest the use of UAVs for bioherding. Given their mobility and speed, UAVs can be used in a wide range of environments and interact with animal groups at sea, over the land, and in the air. 4. We present a potential roadmap for achieving bioherding using a pair of UAVs. In our framework, one UAV performs ‘surveillance’ of animal groups, informing the movement of a second UAV that herds them. We highlight the promise and flexibility of a paired UAV approach, whilst emphasising its practical and ethical challenges. We start by describing the types of experiments and data required to understand individual and collective responses to UAVs. Next, we describe how to develop appropriate herding algorithms. Finally, we describe the integrationof bio-herding algorithms into software and hardware architecture

Intracorporeal Anastomoses in Minimally Invasive Right Colectomies Are Associated With Fewer Incisional Hernias and Shorter Length of Stay

BACKGROUND: Intracorporeal anastomosis is associated with several short-term benefits. However, it is a technically challenging procedure with potential ris

Lymph node yield in right colectomy for cancer: a comparison of open, laparoscopic and robotic approaches

Aim Studies have demonstrated a relationship between lymph node (LN) yield and survival after colectomy for cancer. The impact of surgical technique on LN yield has not been well explored

Long-term safety of pirfenidone: results of the prospective, observational PASSPORT study

Real-world studies include a broader patient population for a longer duration than randomised controlled trials (RCTs) and can provide relevant insights for clinical practice. PASSPORT was a multicentre, prospective, post-authorisation study of patients who were newly prescribed pirfenidone and followed for 2 years after initiating treatment. Physicians collected data on adverse drug reactions (ADRs), serious ADRs (SADRs) and ADRs of special interest (ADRSI) at baseline and then every 3 months. Post hoc stepwise logistic regression models were used to identify baseline characteristics associated with discontinuing treatment due to an ADR. Patients (n=1009, 99.7% with idiopathic pulmonary fibrosis) had a median pirfenidone exposure of 442.0 days. Overall, 741 (73.4%) patients experienced ADRs, most commonly nausea (20.6%) and fatigue (18.5%). ADRs led to treatment discontinuation in 290 (28.7%) patients after a median of 99.5 days. Overall, 55 (5.5%) patients experienced SADRs, with a fatal outcome in six patients. ADRSI were reported in 693 patients, most commonly gastrointestinal symptoms (38.3%) and photosensitivity reactions/skin rashes (29.0%). Older age and female sex were associated with early treatment discontinuation due to an ADR. Findings were consistent with the known safety profile of pirfenidone, based on RCT data and other post-marketing experience, with no new safety signals observed