Bizarre tail weaponry in a transitional ankylosaur from subantarctic Chile.

Armoured dinosaurs are well known for their evolution of specialized tail weapons-paired tail spikes in stegosaurs and heavy tail clubs in advanced ankylosaurs1. Armoured dinosaurs from southern Gondwana are rare and enigmatic, but probably include the earliest branches of Ankylosauria2-4. Here we describe a mostly complete, semi-articulated skeleton of a small (approximately 2 m) armoured dinosaur from the late Cretaceous period of Magallanes in southernmost Chile, a region that is biogeographically related to West Antarctica5. Stegouros elengassen gen. et sp. nov. evolved a large tail weapon unlike any dinosaur: a flat, frond-like structure formed by seven pairs of laterally projecting osteoderms encasing the distal half of the tail. Stegouros shows ankylosaurian cranial characters, but a largely ancestral postcranial skeleton, with some stegosaur-like characters. Phylogenetic analyses placed Stegouros in Ankylosauria; specifically, it is related to Kunbarrasaurus from Australia6 and Antarctopelta from Antarctica7, forming a clade of Gondwanan ankylosaurs that split earliest from all other ankylosaurs. The large osteoderms and specialized tail vertebrae in Antarctopelta suggest that it had a tail weapon similar to Stegouros. We propose a new clade, the Parankylosauria, to include the first ancestor of Stegouros-but not Ankylosaurus-and all descendants of that ancestor.

The rostral micro-tooth morphology of blue marlin, Makaira nigricans.

Billfish rostra potentially have several functions; however, their role in feeding is unequivocal in some species. Recent work linked morphological variation in rostral micro-teeth to differences in feeding behavior in two billfish species, the striped marlin (Kajikia audax) and the sailfish (Istiophorus platypterus). Here, we present the rostral micro-tooth morphology for a third billfish species, the blue marlin (Makaira nigricans), for which the use of the rostrum in feeding behavior is still undocumented from systematic observations in the wild. We measured the micro-teeth on rostrum tips of blue marlin, striped marlin, and sailfish using a micro-computed tomography approach and compared the tooth morphology among the three species. This was done after an analysis of video-recorded hunting behavior of striped marlin and sailfish revealed that both species strike prey predominantly with the first third of the rostrum, which provided the justification to focus our analysis on the rostrum tips. In blue marlin, intact micro-teeth were longer compared to striped marlin but not to sailfish. Blue marlin had a higher fraction of broken teeth than both striped marlin and sailfish, and broken teeth were distributed more evenly on the rostrum. Micro-tooth regrowth was equally low in both marlin species but higher in sailfish. Based on the differences and similarities in the micro-tooth morphology between the billfish species, we discuss potential feeding-related rostrum use in blue marlin. We put forward the hypothesis that blue marlin might use their rostra in high-speed dashes as observed in striped marlin, rather than in the high-precision rostral strikes described for sailfish, possibly focusing on larger prey organisms.

Mapping the neural systems driving breathing at the transition to unconsciousness.

After falling asleep, the brain needs to detach from waking activity and reorganize into a functionally distinct state. A functional MRI (fMRI) study has recently revealed that the transition to unconsciousness induced by propofol involves a global decline of brain activity followed by a transient reduction in cortico-subcortical coupling. We have analyzed the relationships between transitional brain activity and breathing changes as one example of a vital function that needs the brain to readapt. Thirty healthy participants were originally examined. The analysis involved the correlation between breathing and fMRI signal upon loss of consciousness. We proposed that a decrease in ventilation would be coupled to the initial decline in fMRI signal in brain areas relevant for modulating breathing in the awake state, and that the subsequent recovery would be coupled to fMRI signal in structures relevant for controlling breathing during the unconscious state. Results showed that a slight reduction in breathing from wakefulness to unconsciousness was distinctively associated with decreased activity in brain systems underlying different aspects of consciousness including the prefrontal cortex, the default mode network and somatosensory areas. Breathing recovery was distinctively coupled to activity in deep brain structures controlling basic behaviors such as the hypothalamus and amygdala. Activity in the brainstem, cerebellum and hippocampus was associated with breathing variations in both states. Therefore, our brain maps illustrate potential drives to breathe, unique to wakefulness, in the form of brain systems underlying cognitive awareness, self-awareness and sensory awareness, and to unconsciousness involving structures controlling instinctive and homeostatic behaviors.

Haemosporidian parasites in the ash-breasted Sierra finch (Geospizopsis plebejus): insights from an Andean dry forest population.

Haemosporidian genera Plasmodium, Haemoproteus and Leucocytozoon, responsible for avian malarial infections, are highly diverse and have a wide range of health effects and predictors, depending on the host and its environmental context. Here, we present, for the first time, detailed information on the identity, prevalence and parasitaemia of haemosporidians and other haemoparasites that infect the ash-breasted Sierra finch, Geospizopsis plebejus, in an Andean dry forest. We study the consequences of infection in the host body and health conditions and explore the environmental and intrinsic factors that influence infection status and parasitaemia. We conducted diagnoses by cytochrome b (cytb) sequencing and morphological identification, and estimated the levels of parasitaemia based on microscopy. We identified 6 cytb lineages infecting G. plebejus. Two of them were new lineages: Haemoproteus sp. GEPLE01 and GEPLE02. We also detected Haemoproteus sp. ZOCAP08, Haemoproteus sp. AMAVIR01, Plasmodium homopolare BAEBIC02 and Plasmodium cathemerium ZONCAP15. By microscopy, we detected Haemoproteus coatneyi, Haemoproteus erythrogravidus, P. homopolare and other unidentified species of Haemoproteus, Plasmodium, Babesia sp. and 1 microfilaria. We found no evidence of Leucocytozoon. Additionally, we detected several coinfections by sequencing and microscopy. The prevalence of haemosporidian infections was high (87.7%), and the mean parasitaemia was 61.65 infected cells per 10 000 erythrocytes examined. Prevalence and parasitaemia were higher for Haemoproteus than for Plasmodium. Haemoproteus sp. AMAVIR01 showed the highest prevalence (43.1%) and mean parasitaemia (94.39/10 000 erythrocytes) and might be associated with H. coatneyi. Immature individuals showed a lower prevalence than adults, supporting previous findings.

Gemini and Bicephalous Surfactants: A Review on Their Synthesis, Micelle Formation, and Uses.

The use of surfactants in polymerization reactions is particularly important, mainly in emulsion polymerizations. Further, micelles from biocompatible surfactants find use in pharmaceutical dosage forms. This paper reviews recent developments in the synthesis of novel gemini and bicephalous surfactants, micelle formation, and their applications in polymer and nanoparticle synthesis, oil recovery, catalysis, corrosion, protein binding, and biomedical area, particularly in drug delivery.

Identification and genomic characterization of a novel tobamovirus from prickly pear cactus.

In this work, we describe the complete sequence and genome organization of a novel tobamovirus detected in a prickly pear plant (Opuntia sp.) by high-throughput sequencing, tentatively named "opuntia virus 2". The full genome of opuntia virus 2 is 6,453 nucleotides in length and contains four open reading frames (ORFs) coding for the two subunits of the RNA polymerase, the movement protein, and the coat protein, respectively. Phylogenetic analysis using the complete nucleotide sequence revealed that the virus belongs to the genus Tobamovirus (family Virgaviridae), showing the highest nucleotide sequence identity (49.8%) with cactus mild mottle virus (CMMoV), being indicating that it belongs in the Cactaceae subgroup of tobamoviruses.

Avian haemosporidian infections in rufous-collared sparrows in an Andean dry forest: diversity and factors related to prevalence and parasitaemia.

Despite intensive research during the last few decades, understanding of ecological and physiological factors related to haemosporidian infections in birds is still fragmentary. Since more model organisms are needed in order to understand these infections in the wild, we analysed avian haemosporidian infections in the rufous-collared sparrow (Zonotrichia capensis, Emberizidae) in a dry forest of the Ecuadorian Andes. Parasite diversity was screened using molecular and morphological approaches. By molecular diagnosis, we identified three linages that were phylogenetically placed in the context of molecular haemosporidian diversity and associated with a morphospecies. By microscopy, we identified five described morphospecies and one additional undescribed morphospecies. We found that avian haemosporidian prevalence on the study site was 76.3%. Additionally, we used a series of generalized linear models to explore the potential relationship of parasite prevalence and parasitaemia with a set of variables related to physiological and environmental conditions. Although our results revealed associations of haemosporidian infections with precipitation, age and sampling site, the models only explained a small fraction of the variation.

Effect of hospital caseload on long-term outcome after standardization of rectal cancer surgery in the Spanish Rectal Cancer Project. / Influencia del volumen quirúrgico en los resultados oncológicos después de estandarizar la cirugía en el Proyecto Español del Cáncer de Recto.

UNLABELLED: INTRODUCCIóN: The purpose of this prospective multicentre multilevel study was to investigate the influence of hospital caseload on long-term outcomes following standardization of rectal cancer surgery in the Rectal Cancer Project of the Spanish Society of Surgeons. METHODS: Data relating to 2910 consecutive patients with rectal cancer treated for cure between March 2006 and March 2010 were recorded in a prospective database. Hospitals were classified according to number of patients treated per year as low-volume, intermediate-volume, or high volume hospitals (12-23, 24-35, or ≥36 procedures per year). RESULTS: After a median follow-up of 5 years, cumulative rates of local recurrence, metastatic recurrence and overall survival were 6.6 (CI95% 5.6-7.6), 20.3 (CI95% 18.8-21.9) and 73.0 (CI95% 74.7 - 71.3) respectively. In the multilevel regression analysis overall survival was higher for patients treated at hospitals with an annual caseload of 36 or more patients (HR 0,727 [CI95% 0,556-0,951]; P=.02). The risk of local recurrence and metastases were not related to the caseload. Moreover, there was a statistically significant variation in overall survival (median hazard ratio [MHR] 1.184 [CI95% 1.071-1,333]), local recurrence (MHR 1.308 [CI95% 1.010-1.668]) and metastases (MHR 1.300 [CI95% 1.181; 1.476]) between all hospitals. CONCLUSIONS: Overall survival was higher for patients treated at hospitals with an annual caseload of 36 or more patients. However, local recurrence was not influenced by caseload.

[Hospital variation in anastomotic leakage after rectal cancer surgery in the Spanish Association of Surgeons project: The contribution of hospital volume]. / Variabilidad interhospitalaria de la dehiscencia anastomótica en el Proyecto del Cáncer de Recto de la Asociación Española de Cirujanos: La influencia del volumen quirúrgico.

OBJECTIVE: This multicentre observational study aimed to determine the anastomotic leak rate in the hospitals included in the Rectal Cancer Project of the Spanish Society of Surgeons and examine whether hospital volume may contribute to any variation between hospitals. METHODS: Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all adenocarcinomas of the rectum operated by an anterior resection at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, use of defunctioning stoma, tumour location and stage, administration of neoadjuvant treatment, and annual volume of elective surgical procedures. RESULTS: A total of 7231 consecutive patients were included. The rate of anastomotic leak was 10.0%. Stratified by annual surgical volume hospitals varied from 9.9 to 11.3%. In multilevel regression analysis, the risk of anastomotic leak increased in male patients, in patients with tumours located below 12 cm from the anal verge, and advanced tumour stages. However, a defunctioning stoma seemed to prevent this complication. Hospital surgical volume was not associated with anastomotic leak (OR: 0.852, [0.487-1.518]; P=.577). Furthermore, there was a statistically significant variation in anastomotic leak between all departments (MOR: 1.475; [1.321-1.681]; P<0.001). CONCLUSION: Anastomotic leak varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume.

Hospital variability in postoperative mortality after rectal cancer surgery in the Spanish Association of Surgeons project: The impact of hospital volume.

OBJECTIVE: This multicentre observational study examines variation between hospitals in postoperative mortality after elective surgery in the Rectal Cancer Project of the Spanish Society of Surgeons and explores whether hospital volume and patient characteristics contribute to any variation between hospitals. METHODS: Hospital variation was quantified using a multilevel approach on prospective data derived from the multicentre database of all rectal adenocarcinomas operated by an anterior resection or an abdominoperineal excision at 84 surgical departments from 2006 to 2013. The following variables were included in the analysis; demographics, American Society of Anaesthesiologists classification, tumour location and stage, administration of neoadjuvant treatment, and annual volume of surgical procedures. RESULTS: A total of 9809 consecutive patients were included. The rate of 30-day postoperative mortality was 1.8% Stratified by annual surgical volume hospitals varied from 1.4 to 2.0 in 30-day mortality. In the multilevel regression analysis, male gender (OR 1.623 [1.143; 2.348]; P<.008), increased age (OR: 5.811 [3.479; 10.087]; P<.001), and ASA score (OR 10.046 [3.390; 43.185]; P<.001) were associated with 30-day mortality. However, annual surgical volume was not associated with mortality (OR 1.309 [0.483; 4.238]; P=.619). Besides, there was a statistically significant variation in mortality between all departments (MOR 1.588 [1.293; 2.015]; P<.001). CONCLUSION: Postoperative mortality varies significantly among hospitals included in the project and this difference cannot be attributed to the annual surgical volume.

Multicenter study of outcome in relation to the type of resection in rectal cancer.

BACKGROUND: A surgical teaching and auditing program has been implemented to improve the results of treatment for patients with rectal cancer. OBJECTIVE: The aim of this study was to assess the treatment and outcome in patients resected for rectal cancer, focusing on differences relating to the type of resection. DESIGN: This was an observational study. SETTINGS: The study took place throughout the network of hospitals that compose the National Health Service in Spain. PATIENTS: This study included a consecutive cohort of 3355 patients from the Spanish Rectal Cancer Project. The data of patients who were operated on electively, with curative intent, by anterior resection (n = 2333 [69.5%]), abdominoperineal excision (n = 774 [23.1%]), and Hartmann procedure (n = 248 [7.4%]) between March 2006 and May 2010 were analyzed. MAIN OUTCOME MEASURES: Clinical, pathologic, and outcome results were analyzed in relation to the type of surgery performed. RESULTS: After a median follow-up time of 37 months (interquartile range, 30-48 months), bowel perforations were found to be more common in the Hartmann procedure (12.6%) and abdominoperineal groups (10.1%) than in the anterior resection group (2.3%; p < 0.001). Involvement of the circumferential resection margin was also more common in the Hartmann (16.6%) and abdominoperineal groups (14.3%) than in the anterior resection group (6.6%; p < 0.001). Multivariate analysis showed a negative influence on local recurrence, metastasis, survival for advanced stage, intraoperative perforation, invaded circumferential margin, and Hartmann procedure. However, abdominoperineal excision did not significantly influence local recurrence (HR, 0.945; 95% CI, 0.571-1.563; p = 0.825). LIMITATIONS: The main weakness of this study was the voluntary nature of registration in the Spanish Rectal Cancer Project. CONCLUSIONS: Although bowel perforation and involvement of the circumferential resection margin were more common after abdominoperineal excision than after anterior resection, this study did not identify abdominoperineal excision as a determinant of local recurrence in the context of 3 years of median follow-up.

Anatomic Areas of Lipoframing in Breast Surgery.

Breast lipoframing is a concept in breast surgery that encompasses the often-overlooked aspects of the mammary glands, such as the surrounding structures and adipose tissue within the thorax. By acknowledging the interplay between these components and recognizing the need for their simultaneous treatment, breast lipoframing aims to optimize surgical aesthetic outcomes. This article proposes a comprehensive definition of the surrounding mammary fat tissue by delineating the specific areas of the breast involved in the lipoframing technique. It presents a retrospective analysis of 554 female patients, revealing only one case of seroma and three cases of hematoma. Furthermore, we explore the application of liposuction as a means to effectively treat these areas and achieve superior results.

Central American and Caribbean Consensus Document for the Optimal Management of Oral Anticoagulation in Patients with Non-Valvular Atrial Fibrillation Endorsed by the Central American and Caribbean Society of Arterial Hypertension and Cardiovascular Prevention.

Atrial fibrillation (AF) is the most common arrhythmia in adults. Prevention of the ischaemic risk with oral anticoagulants (OACs) is widely recommended, and current clinical guidelines recommend direct oral anticoagulants (DOACs) as preference therapy for stroke prevention. However, there are currently no clinical practice guidelines or recommendation documents on the optimal management of OACs in patients with AF that specifically address and adapt to the Central American and Caribbean context. The aim of this Delphi-like study is to respond to doubts that may arise in the management of OACs in patients with non-valvular AF in this geographical area. A consensus project was performed on the basis of a systematic review of the literature, a recommended ADOLOPMENT-like approach, and the application of a two-round Delphi survey. In the first round, 31 recommendations were evaluated and 30 reached consensus, of which, 10 unanimously agreed. The study assessed expert opinions in a wide variety of contextualized recommendations for the optimal management of DOACs in patients with non-valvular atrial fibrillation (NVAF). There is a broad consensus on the clinical practice guideline (CPG) statements used related to anticoagulation indication, patient follow-up, anticoagulation therapy complications, COVID-19 management and prevention, and cardiac interventions.

Distinct interactions stabilize EGFR dimers and higher-order oligomers in cell membranes.

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase with important roles in many cellular processes as well as in cancer and other diseases. EGF binding promotes EGFR dimerization and autophosphorylation through interactions that are well understood structurally. How these dimers relate to higher-order EGFR oligomers seen in cell membranes, however, remains unclear. Here, we used single-particle tracking (SPT) and Förster resonance energy transfer imaging to examine how each domain of EGFR contributes to receptor oligomerization and the rate of receptor diffusion in the cell membrane. Although the extracellular region of EGFR is sufficient to drive receptor dimerization, we find that the EGF-induced EGFR slowdown seen by SPT requires higher-order oligomerization-mediated in part by the intracellular tyrosine kinase domain when it adopts an active conformation. Our data thus provide important insight into the interactions required for higher-order EGFR assemblies involved in EGF signaling.

[The Spanish Association of Surgeon's audited teaching programme for rectal cancer. Results after six years]. / Resultados del proyecto docente y auditado del cáncer de recto de la Asociación Española de Cirujanos. Seis años desde su inicio.

BACKGROUND: The Spanish Rectal Cancer Project of the Spanish Association of Surgeons was established in 2006. The main objective of this observational study was to assess the results obtained by the hospitals trained in the period 2006-2011, in order to evaluate whether this initiative has allowed acheivement of the observed quality standards in the Norwegian Rectal Cancer Project. METHODS: Between March 2006 and June 2012 a cohort of 10,006 patients treated during 2006-2011 in 79 hospitals were included in the project registry. In 8.706 (94.5%) patients a rectal resection was performed. In 1.156 patients diagnosed with metastases or an R2-resection, the resection was considered palliative. The number of rectal resections with curative intent analyzed was 7.396 (80.3%). The outcome measures of the program effectiveness were local recurrence, metastases and survival. RESULTS: After a median follow-up period of 19.0 months (interquartile range [8.00-33.0]), local recurrence rate was 7.7 (9.1-6.2); metastases, 23.4 (25.6-21.1), and mortality 25.9 (28.1-23.7). CONCLUSION: This study shows that the oncological results achieved by the Spanish hospitals participating in the Rectal Cancer Project of the Spanish Association of Surgeons are similar to those observed in the Norwegian Colon and Rectal Cancer Project.

Architecture Optimization of a Non-Linear Autoregressive Neural Networks for Mackey-Glass Time Series Prediction Using Discrete Mycorrhiza Optimization Algorithm.

Recurrent Neural Networks (RNN) are basically used for applications with time series and sequential data and are currently being used in embedded devices. However, one of their drawbacks is that RNNs have a high computational cost and require the use of a significant amount of memory space. Therefore, computer equipment with a large processing capacity and memory is required. In this article, we experiment with Nonlinear Autoregressive Neural Networks (NARNN), which are a type of RNN, and we use the Discrete Mycorrhizal Optimization Algorithm (DMOA) in the optimization of the NARNN architecture. We used the Mackey-Glass chaotic time series (MG) to test the proposed approach, and very good results were obtained. In addition, some comparisons were made with other methods that used the MG and other types of Neural Networks such as Backpropagation and ANFIS, also obtaining good results. The proposed algorithm can be applied to robots, microsystems, sensors, devices, MEMS, microfluidics, piezoelectricity, motors, biosensors, 3D printing, etc.

Synthesis and Characterization of a pH- and Temperature-Sensitive Fe3O4-SiO2-Poly(NVCL-co-MAA) Nanocomposite for Controlled Delivery of Doxorubicin Anticancer Drug.

This work reports the synthesis, characterization, and in vitro release studies of pH- and temperature-sensitive Fe3O4-SiO2-poly(NVCL-co-MAA) nanocomposite. Fe3O4 nanoparticles were prepared by chemical coprecipitation, coated with SiO2 by the Stöber method, and functionalized with vinyl groups. The copolymer poly(N-vinylcaprolactam-co-methacrylic acid) (poly(NVCL-co-MAA)) was grafted onto the functionalized Fe3O4-SiO2 nanoparticles by free radical polymerization. XRD, FTIR, TGA, VSM, and TEM techniques were performed to characterize the nanocomposite. The release behavior of Doxorubicin (DOX) loaded in the nanocomposite at pH 5.8 and 7.4, and two temperatures, 25 and 37 °C, was studied. According to the release studies, approximately 55% of DOX is released in 72 h at pH 7.4, regardless of temperature. At pH 5.8, 78% of DOX was released in 48 h at 25 °C, and when increasing the temperature to 37 °C, more than 95 % of DOX was released in 24 h. The DOX release data treated with Zero-order, first-order, Higuchi, and Korsmeyer-Peppas models showed that Higuchi's model best fits the data, indicating that the DOX is released by diffusion. The findings suggest that the synthesized nanocomposite may be useful as a DOX carrier in biomedical applications.

Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile.

In the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, Gonkoken nanoi, of early Maastrichtian age in Magallanes, Chile. Unlike duckbills further north in Patagonia, Gonkoken descends from North American forms diverging shortly before the origin of Hadrosauridae. However, at the time, non-hadrosaurids in North America had become replaced by hadrosaurids. We propose that the ancestors of Gonkoken arrived earlier in South America and reached further south, into regions where hadrosaurids never arrived: All alleged subantarctic and Antarctic remains of hadrosaurids could belong to non-hadrosaurid duckbills like Gonkoken. Dinosaur faunas of the world underwent qualitatively different changes before the Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability.

Distinct interactions stabilize EGFR dimers and higher-order oligomers in cell membranes.

The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase (RTK) with important roles in many cellular processes as well as cancer and other diseases. EGF binding promotes EGFR dimerization and autophosphorylation through interactions that are well understood structurally. However, it is not clear how these dimers relate to higher-order EGFR oligomers detected at the cell surface. We used single-particle tracking (SPT) and Förster resonance energy transfer (FRET) imaging to examine how each domain within EGFR contributes to receptor dimerization and the rate of its diffusion in the cell membrane. We show that the EGFR extracellular region is sufficient to drive receptor dimerization, but that the EGF-induced EGFR slow-down seen by SPT requires formation of higher order oligomers, mediated in part by the intracellular tyrosine kinase domain - but only when in its active conformation. Our data thus provide important insight into higher-order EGFR interactions required for EGF signaling.