bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of Bowel Preparation in Colorectal Surgery
Authors: Klinger Aaron L. , Green Heather , Monlezun Dominique J. , Beck David , Kann Brian , Vargas Herschel D. , Whitlow Charles , Margolin David 
Published: October 2017

Objective:To analyze potential benefits with regards to infectious complications with combined use of mechanical bowel preparation (MBP) and ABP in elective colorectal resections.Background:Despite recent literature suggesting that MBP does not reduce infection rate, it still is commonly used. The use of oral antibiotic bowel preparation (ABP) has been practiced for decades but its use is also controversial.Methods:Patients undergoing elective colorectal resection in the 2012 to 2015 American College of Surgeons National Surgical Quality Improvement Program cohorts were selected. Doubly robust propensity score–adjusted multivariable regression was conducted for infectious and other postoperative complications.Results:A total of 27,804 subjects were analyzed; 5471 (23.46%) received no preparation, 7617 (32.67%) received MBP only, 1374 (5.89%) received ABP only, and 8855 (37.98%) received both preparations. Compared to patients receiving no preparation, those receiving dual preparation had less surgical site infection (SSI) [odds ratio (OR) = 0.39,P< 0.001], organ space infection (OR = 0.56,P ≤ 0.001), wound dehiscence (OR = 0.43,P= 0.001), and anastomotic leak (OR = 0.53,P< 0.001). ABP alone compared to no prep resulted in significantly lower rates of surgical site infection (OR = 0.63,P= 0.001), organ space infection (OR = 0.59,P= 0.005), anastomotic leak (OR = 0.53,P= 0.002). MBP showed no significant benefit to infectious complications when used as monotherapy.Conclusions:Combined MBP/ABP results in significantly lower rates of SSI, organ space infection, wound dehiscence, and anastomotic leak than no preparation and a lower rate of SSI than ABP alone. Combined bowel preparation significantly reduces the rates of infectious complications in colon and rectal procedures without increased risk ofClostridium difficileinfection. For patients undergoing elective colon or rectal resection we recommend bowel preparation with both mechanical agents and oral antibiotics whenever feasible.
Variation in Drain Management After Pancreatoduodenectomy
Authors: Beane Joal D. , House Michael G. , Ceppa Eugene P. , Dolejs Scott C. , Pitt Henry A. 
Published: October 2017

Objective:
The objectives are to report practice patterns and management of operatively placed drains and to compare outcomes in patients with early versus delayed drain removal after pancreatoduodenectomy.

Background:
Early drain removal after pancreatoduodenectomy, when guided by postoperative day (POD) 1 drain fluid amylase (DFA-1), is associated with reduced rates of clinically relevant postoperative pancreatic fistula (CR-POPF). However, whether surgeons have altered their management based on this strategy is unknown.

Methods:
The American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) 2014 Participant Use File was queried to identify patients having undergone pancreatoduodenectomy (n = 3093). Patients with intraoperatively placed drains were stratified according to measurement of DFA-1 and day of drain removal. Patients with POD 1 DFA-1 of ≤5000 U/L whose drains were removed by POD 3 were propensity score-matched with patients whose drains were removed after POD 3.

Results:
Of 2698 patients, 580 (21.5%) had a DFA-1 recorded. Measurement of DFA-1 was associated with earlier time to drain removal and shorter postoperative length of stay (P < 0.01). Propensity score matching revealed that early drain removal when DFA-1 was ≤5000 U/L was associated with significant (P < 0.05) reductions in overall morbidity (35.3% vs 52.3%), CR-POPF (0.9% vs 7.9%), and length of stay (6 vs 8 days).

Conclusions:
Significant variation exists in the use of drain fluid amylase in the management and timing of surgical drain removal after pancreatoduodenectomy. Clinical outcomes are best when drain fluid amylase is low and operatively placed drains are removed by POD 3.
Transplantation Versus Resection for Hilar Cholangiocarcinoma
Authors: Ethun Cecilia G. , Lopez-Aguiar Alexandra G. , Anderson Douglas J. , Adams Andrew B. , Fields Ryan C. , Doyle Maria B. , Chapman William C. , Krasnick Bradley A. , Weber Sharon M. , Mezrich Joshua D. , Salem Ahmed , Pawlik Timothy M. , Poultsides George , Tran Thuy B. , Idrees Kamran , Isom Chelsea A. , Martin Robert C. G. , Scoggins Charles R. , Shen Perry , Mogal Harveshp D. , Schmidt Carl , Beal Eliza , Hatzaras Ioannis , Shenoy Rivfka , Cardona Kenneth , Maithel Shishir K. 
Published: October 2017

Objective:
To investigate the influence of type of surgery (transplant vs resection) on overall survival (OS) in patients with hilar cholangiocarcinoma (H-CCA).

Background:
Outcomes after resection for H-CCA are poor, yet transplantation is currently only reserved for well-selected patients with unresectable disease.

Methods:
All patients with H-CCA who underwent resection from 2000 to 2015 at 10 institutions were included. Three institutions additionally had active H-CCA transplant protocols with similar selection criteria over similar time periods.

Results:
Of 304 patients with suspected H-CCA, 234 underwent attempted resection and 70 were enrolled in a transplant protocol. Excluding incomplete/R2 resections (n = 43), patients who were enrolled, but did not undergo transplant (n = 24), and transplants without confirmed H-CCA diagnoses (n = 5), 191 patients underwent curative-intent resection and 41 curative-intent transplant. Compared with resection, transplant patients were younger (52 vs 65 years; P < 0.001), and more frequently had primary sclerosing cholangitis (PSC; 61% vs 2%; P < 0.001) and received chemotherapy and/or radiation (98% vs 57%; P < 0.001). Groups were otherwise similar in demographics and comorbidities. Patients who underwent transplant for confirmed H-CCA diagnosis had improved OS compared with resection (3-year: 72% vs 33%; 5-year: 64% vs 18%; P < 0.001). Among patients who underwent resection for tumors <3 cm with lymph-node negative disease, and excluding PSC patients, transplant was still associated with improved OS (3-year: 54% vs 44%; 5-year: 54% vs 29%; P = 0.03). Transplant remained associated with improved survival on intention-to-treat analysis, even after accounting for tumor size, lymph node status, and PSC (P = 0.049).

Conclusions:
Resection for hilar cholangiocarcinoma that meets criteria for transplantation (<3 cm, lymph-node negative disease) is associated with substantially decreased survival compared to transplant for the same criteria with unresectable disease. Prospective trials are needed and justified.
The Successful Implementation of a Modified Enhanced Recovery After Surgery (ERAS) Program for Bariatric Surgery in a South African Teaching Hospital
Authors: Loots Emil , Sartorius Benn , Paruk Imran M. , Clarke Damian L. 
Published: October 2017

Background:
This study assessed the impact of strict adherence to perioperative pathways incorporating an enhanced recovery after surgery protocol on the outcomes of bariatric surgery at our center.

Methods:
Prospective data were collected on 62 patients undergoing bariatric surgery between January 2011 and March 2016. Outcomes were compared between those who adhered to the perioperative pathway and those who did not.

Results:
Fifty-three patients underwent laparoscopic sleeve gastrectomy, and 9 patients underwent Laparoscopic Roux-en-Y Gastric Bypass. The majority of subjects were female individuals (n=45; 72.6%). The mean age (±SD) was 40.5±9.8 years (range, 21 to 59 y). The mean preoperative body mass index (BMI) was 54.8±11.0. The mean BMI loss from baseline was 14.8 kg/m2 (−15.9 kg m2; P<0.001). There were no deaths, and there were only 2 postoperative complications (1 intra-abdominal bleeding postoperatively requiring reoperation and 1 patient requiring CPAP support in intensive care unit). Full adherence was achieved in 53 (85.5%) patients with a mean length of stay (LOS) of 3±0.8 days. The nonadherent group had a significantly longer LOS of 4±3.2 days (P=0.049). The time since last follow-up visit was on average 4.4±5.6 months in the fully adherent group and significantly longer in the nonadherent group at 10.6±11.3 months (P=0.013). Age, race, sex, and BMI did not significantly impact on adherence. The mean LOS among morbidly obese and super obese patients was comparable at 3 and 3.3 days, respectively (P=0.442).

Conclusion:
Adherence to enhanced recovery after surgery pathways was associated with a significantly shorter hospital stay and better follow-up in our surgical unit.
Anal Sphincter Anatomy Prepregnancy to Postdelivery Among the Same Primiparous Women on Dynamic Magnetic Resonance Imaging
Authors: Meriwether Kate V. , Lockhart Mark E. , Meyer Isuzu , Richter Holly E. 
Published: October 2017

Objectives
The authors used 2-dimensional images from pelvic 3 T magnetic resonance imaging (MRI) to characterize changes in the internal anal sphincter (IAS) and external anal sphincter (EAS) from prepregnancy to postdelivery in the same cohort.

Methods
This secondary analysis studied a prospective cohort of women undergoing 3 T MRI before their first pregnancy and 6 or more months after delivery. Radial thickness was measured at 12, 3, 9, and 6 o'clock from axial proximal and mid views and oblique distal views of the IAS, and at 3 and 9 o'clock from oblique views of the EAS. Measurements were compared prepregnancy to postdelivery; 10 women had 80% power (α = 0.05) to detect a 0.85-mm change.

Results
Nineteen women completed initial 3 T MRI, 15 achieved pregnancy and birth, and 10 completed postdelivery MRI (4 vaginal birth and 6 Cesarean delivery). Mean change in measurement from prepregnancy to postdelivery was −0.01 mm ± 1.03 mm for the distal 12 o'clock IAS (P = 0.98) and +0.19 ± 0.64 mm for the lateral EAS (P = 0.32). All prepregnancy and postdelivery women had discontinuous EA sphincters at 6 and 12 o'clock. There were no statistically significant changes from prepregnancy to postdelivery in any IAS or EAS location (all >0.05) for the entire cohort, those with vaginal birth, or after Cesarean.

Conclusions
Anal sphincter measurements on MRI did not change significantly in nulliparous women prepregnancy to postdelivery at any location, and the EAS was not measurable at 12 o'clock in any women at either time point, challenging classic concepts of EAS anatomy.
Nascent life cycles and the emergence of higher-level individuality
Authors: Ratcliff William C. , Herron Matthew , Conlin Peter L. , Libby Eric 
Published: October 2017

Evolutionary transitions in individuality (ETIs) occur when formerly autonomous organisms evolve to become parts of a new, ‘higher-level’ organism. One of the first major hurdles that must be overcome during an ETI is the emergence of Darwinian evolvability in the higher-level entity (e.g. a multicellular group), and the loss of Darwinian autonomy in the lower-level units (e.g. individual cells). Here, we examine how simple higher-level life cycles are a key innovation during an ETI, allowing this transfer of fitness to occur ‘for free’. Specifically, we show how novel life cycles can arise and lead to the origin of higher-level individuals by (i) mitigating conflicts between levels of selection, (ii) engendering the expression of heritable higher-level traits and (iii) allowing selection to efficiently act on these emergent higher-level traits. Further, we compute how canonical early life cycles vary in their ability to fix beneficial mutations via mathematical modelling. Life cycles that lack a persistent lower-level stage and develop clonally are far more likely to fix ‘ratcheting’ mutations that limit evolutionary reversion to the pre-ETI state. By stabilizing the fragile first steps of an evolutionary transition in individuality, nascent higher-level life cycles may play a crucial role in the origin of complex life.
This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.
The topology of evolutionary novelty and innovation in macroevolution
Authors: Erwin Douglas H. 
Published: October 2017

Sewall Wright's fitness landscape introduced the concept of evolutionary spaces in 1932. George Gaylord Simpson modified this to an adaptive, phenotypic landscape in 1944 and since then evolutionary spaces have played an important role in evolutionary theory through fitness and adaptive landscapes, phenotypic and functional trait spaces, morphospaces and related concepts. Although the topology of such spaces is highly variable, from locally Euclidean to pre-topological, evolutionary change has often been interpreted as a search through a pre-existing space of possibilities, with novelty arising by accessing previously inaccessible or difficult to reach regions of a space. Here I discuss the nature of evolutionary novelty and innovation within the context of evolutionary spaces, and argue that the primacy of search as a conceptual metaphor ignores the generation of new spaces as well as other changes that have played important evolutionary roles.This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.
Innovation and social transmission in experimental micro-societies: exploring the scope of cumulative culture in young children
Authors: McGuigan Nicola , Burdett Emily , Burgess Vanessa , Dean Lewis , Lucas Amanda , Vale Gillian , Whiten Andrew 
Published: October 2017

The experimental study of cumulative culture and the innovations essential to it is a young science, with child studies so rare that the scope of cumulative cultural capacities in childhood remains largely unknown. Here we report a new experimental approach to the inherent complexity of these phenomena. Groups of 3–4-year-old children were presented with an elaborate array of challenges affording the potential cumulative development of a variety of techniques to gain increasingly attractive rewards. In contrast to a prior study, we found evidence for elementary forms of cumulative cultural progress, with inventions of solutions at lower levels spreading to become shared innovations, and some children then building on these to create more advanced but more rewarding innovations. This contrasted with markedly more constrained progress when children worked only by themselves, or if groups faced only the highest-level challenges from the start. Further experiments that introduced higher-level inventions via the inclusion of older children, or that created ecological change, with the easiest habitual solutions no longer possible, encouraged higher levels of cumulative innovation. Our results show children are not merely ‘cultural sponges’, but when acting in groups, display the beginnings of cycles of innovation and observational learning that sustain cumulative progress in problem solving.
This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.
Cognitive innovations and the evolutionary biology of expertise
Authors: Dukas Reuven 
Published: October 2017

Animal life can be perceived as the selective use of information for maximizing survival and reproduction. All organisms including bacteria and protists rely on genetic networks to build and modulate sophisticated structures and biochemical mechanisms for perceiving information and responding to environmental changes. Animals, however, have gone through a series of innovations that dramatically increased their capacity to acquire, retain and act upon information. Multicellularity was associated with the evolution of the nervous system, which took over many tasks of internal communication and coordination. This paved the way for the evolution of learning, initially based on individual experience and later also via social interactions. The increased importance of social learning also led to the evolution of language in a single lineage. Individuals' ability to dramatically increase performance via learning may have led to an evolutionary cycle of increased lifespan and greater investment in cognitive abilities, as well as in the time necessary for the development and refinement of expertise. We still know little, however, about the evolutionary biology, genetics and neurobiological mechanisms that underlie such expertise and its development.
This article is part of the themed issue ‘Process and pattern in innovations from cells to societies’.
Meaning Guides Attention in Real-World Scene Images: Evidence from Eye Movements and Meaning Maps
Authors: Henderson John M. , Hayes Taylor R. 
Published: October 2017

AbstractWe compared the influences of meaning and salience on attentional guidance in scene images. Meaning was captured by “meaning maps” representing the spatial distribution of semantic information in scenes. Meaning maps were coded in a format that could be directly compared to maps of image salience generated from image features. We investigated the degree to which meaning versus image salience predicted human viewers’ spatial distribution of attention over scenes, with attention operationalized as duration-weighted fixation density. The results showed that both meaning and salience predicted the distribution of attention, but that when the correlation between meaning and salience was statistically controlled, meaning accounted for unique variance in attention but salience did not. This pattern was observed for early as well as late fixations, for fixations following short as well as long saccades, and for fixations including or excluding the centers of the scenes. The results strongly suggest that meaning guides attention in real world scenes. We discuss the results from the perspective of a cognitive relevance theory of attentional guidance in scenes.
Contribution of transition and stabilization processes to speciation is a function of the ancestral trait state and selective environment in Hakea
Authors: Lamont Byron B. , El-ahmir Sh-hoob M. , Lim Sim Lin , Groom Philip K. , He Tianhua 
Published: October 2017

ABSTRACTCurrently the origin and trajectories of novel traits are emphasised in evolutionary studies, the role of stabilization is neglected, and interpretations are often post hoc rather than as hypothesised responses to stated agents of selection. Here we evaluated the impact of changing environmental conditions on trait evolution and stabilization and their relative contribution to diversification in a prominent Australian genus, Hakea (Proteaceae). We assembled a time-based phylogeny for Hakea, reconstructed its ancestral traits for six attributes and determined their evolutionary trajectories in response to the advent or increasing presence of fire, seasonality, aridity, nectar-feeding birds and (in)vertebrate herbivores/granivores. The ancestral Hakea arose 18 million years ago (Ma) and was broad-leaved, non-spinescent, insect-pollinated, had medium-sized, serotinous fruits and resprouted after fire. Of the 190 diversification events that yielded the 82 extant species analysed, 8–50% involved evolution, stabilization or re-evolution (reversal) of individual novel traits. Needle leaves appeared 14 Ma and increased through the Neogene/Quaternary coinciding with intensifying seasonality and aridity. Spinescence arose 12 Ma consistent with the advent of vertebrate herbivores. Bird-pollination appeared 14 Ma in response to advent of the Meliphagidae in the early Miocene. Small and large woody fruits evolved from 12 Ma as alternative defenses against granivory. Fire-caused death evolved 14 Ma, accounting for 50% of subsequent events, as fire became less stochastic. Loss of serotiny began in the late Miocene as non-fireprone habitats became available but only contributed 8% of events. Innovation and subsequent stabilization of functional traits promoted the overall species diversification rate in Hakea by 15 times such that only three species now retain the ancestral phenotype. Our approach holds great promise for understanding the processes responsible for speciation of organisms when the ancestral condition can be identified and the likely selective agents are understood.
Bipolar filaments of human nonmuscle myosin 2-A and 2-B have distinct motile and mechanical properties
Authors: Melli Luca , Billington Neil , Sun Sara A. , Bird Jonathan E. , Nagy Attila , Friedman Thomas B. , Takagi Yasuharu , Sellers James R. 
Published: October 2017

AbstractNonmuscle myosin 2 (NM-2) powers cell motility and tissue morphogenesis by assembling into bipolar filaments that interact with actin. Although the enzymatic properties of purified NM-2 motor fragments have been determined, the emergent properties of filament ensembles are unknown. Using single myosin filament in vitro motility assays, we report fundamental differences in filaments formed of different NM-2 motors. Filaments consisting of NM2-B moved processively along actin, while under identical conditions, NM2-A filaments did not. By more closely mimicking the physiological milieu, either by increasing solution viscosity or by copolymerization with NM2-B, NM2-A containing filaments moved processively. Our data demonstrate that both the kinetic and mechanical properties of these two myosins, in addition to the stochiometry of NM-2 subunits, can tune filament mechanical output. We propose altering NM-2 filament composition is a general cellular strategy for tailoring force production of filaments to specific functions such as maintaining tension or remodeling actin.
Distinct contributions of functional and deep neural network features to representational similarity of scenes in human brain and behavior
Authors: Groen Iris I. A. , Greene Michelle R. , Baldassano Christopher , Fei-Fei Li , Beck Diane M. , Baker Chris I. 
Published: October 2017

AbstractInherent correlations between visual and semantic features in real-world scenes make it difficult to determine how different scene properties contribute to neural representations. Here, we assessed the contributions of multiple properties to scene representation by partitioning the variance explained in human behavioral and brain measurements by three feature models whose inter-correlations were minimizeda priorithrough stimulus preselection. Behavioral assessments of scene similarity reflected unique contributions from a functional feature model indicating potential actions in scenes as well as high-level visual features from a deep neural network (DNN). In contrast, similarity of cortical responses in scene-selective areas was uniquely explained by mid- and high-level DNN features only, while an object label model did not contribute uniquely to either domain. The striking dissociation between functional and DNN features in their contribution to behavioral and brain representations of scenes indicates that scene-selective cortex represents only a subset of behaviorally relevant scene information.