Phylogenomics and the rise of the angiosperms.

Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5-7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.

Intra-nucleus mosaic pattern (InMop) and whole-cell Haralick combined-descriptor for identifying and characterizing acute leukemia blasts on single cell peripheral blood images.

Acute leukemia is usually diagnosed when a test of peripheral blood shows at least 20% of abnormal immature cells (blasts), a figure even lower in case of recurrent cytogenetic abnormalities. Blast identification is crucial for white blood cell (WBC) counting, which depends on both identifying the cell type and characterizing the cellular morphology, processes susceptible of inter- and intraobserver variability. The present work introduces an image combined-descriptor to detect blasts and determine their probable lineage. This strategy uses an intra-nucleus mosaic pattern (InMop) descriptor that captures subtle nuclei differences within WBCs, and Haralick's statistics which quantify the local structure of both nucleus and cytoplasm. The InMop captures WBC inner-nucleus structure by applying a multiscale Shearlet decomposition over a repetitive pattern (mosaic) of automatically-segmented nuclei. As a complement, Haralick's statistics characterize the local structure of the whole cell from an intensity co-occurrence matrix representation. Both InMoP and Haralick-based descriptors are calculated using the b-channel from Lab color-space. The combined-descriptor is assessed by differentiating blasts from nonleukemic cells with support vector machine (SVM) classifiers and different transformation kernels, in two public and independent databases. The first database-D1 (n = 260) is composed of healthy and acute lymphoid leukemia (ALL) single cell images, and second database-D2 contains acute myeloid leukemia (AML) blasts (n = 3294) and nonblast (n = 15,071) cell images. In a first experiment, blasts versus nonblast differentiation is performed by training with a subset of D2 (n = 6588) and testing in D1 (n = 260), obtaining a training AUC of 0.991 ± 0.002 and AUC = 0.782 for the independent validation. A second experiment automatically differentiates AML blasts (260 images from D2) from ALL blasts (260 images from D1), with an AUC of 0.93. In a third experiment, state-of-the-art strategies, VGG16 and RESNEXT convolutional neural networks (CNN), separate blast from nonblast cells in both databases. The VGG16 showed an AUC of 0.673 and the RESNEXT of 0.75. Reported metrics for all the experiments are area under the ROC curve (AUC), accuracy and F1-score.

Zinc-Doped Iron Oxide Nanoparticles as a Proton-Activatable Agent for Dose Range Verification in Proton Therapy.

Proton therapy allows the treatment of specific areas and avoids the surrounding tissues. However, this technique has uncertainties in terms of the distal dose fall-off. A promising approach to studying the proton range is the use of nanoparticles as proton-activatable agents that produce detectable signals. For this, we developed an iron oxide nanoparticle doped with Zn (IONP@Zn-cit) with a hydrodynamic size of 10 nm and stability in serum. Cytotoxicity, defined as half of the surveillance, was 100 µg Zn/mL in the U251 cell line. The effect on clonogenic cell death was tested after X-ray irradiation, which suggested a radioprotective effect of these nanoparticles at low concentrations (1-10 µg Zn/mL). To evaluate the production of positron emitters and prompt-gamma signals, IONP@Zn-cit was irradiated with protons, obtaining prompt-gamma signals at the lowest measured concentration (10 mg Zn/mL). Finally, 67Ga-IONP@Zn-cit showed accumulation in the liver and spleen and an accumulation in the tumor tissue of 0.95% ID/g in a mouse model of U251 cells. These results suggest the possibility of using Zn nanoparticles as proton-activatable agents to verify the range by prompt gamma detection and face the challenges of prompt gamma detection in a specific biological situation, opening different avenues to go forward in this field.

Differential development of large-cell neuroendocrine or small-cell lung carcinoma upon inactivation of 4 tumor suppressor genes.

High-grade neuroendocrine lung malignancies (large-cell neuroendocrine cell carcinoma, LCNEC, and small-cell lung carcinoma, SCLC) are among the most deadly lung cancer conditions with no optimal clinical management. The biological relationships between SCLC and LCNEC are still largely unknown and a current matter of debate as growing molecular data reveal high heterogeneity with potential therapeutic consequences. Here we describe murine models of high-grade neuroendocrine lung carcinomas generated by the loss of 4 tumor suppressors. In an Rbl1-null background, deletion of Rb1, Pten, and Trp53 floxed alleles after Ad-CMVcre infection in a wide variety of lung epithelial cells produces LCNEC. Meanwhile, inactivation of these genes using Ad-K5cre in basal cells leads to the development of SCLC, thus differentially influencing the lung cancer type developed. So far, a defined model of LCNEC has not been reported. Molecular and transcriptomic analyses of both models revealed strong similarities to their human counterparts. In addition, a 68Ga-DOTATOC-based molecular-imaging method provides a tool for detection and monitoring the progression of the cancer. These data offer insight into the biology of SCLC and LCNEC, providing a useful framework for development of compounds and preclinical investigations in accurate immunocompetent models.

Two-photon absorption properties of BODIPY-like compounds based on BF2-naphthyridine complexes.

Boron dipyrromethene type molecules (BODIPYs) are versatile molecules which have been used for applications ranging from photodynamic therapy to solar cells (DSSC). However, these molecules usually do not present high two-photon absorption cross-sections, limiting their use in nonlinear optical applications. Herein, we study a series of BF2-naphthyridine based boron-complexes with electron-donating and withdrawing groups to increase their two-photon absorption. We have found two-photon absorption cross-sections up to approximately 270 GM, which corresponds to an increase of approximately five times in comparison to the average cross-section value reported for molecules with similar conjugation length, indicating such compounds as potential materials for nonlinear applications in both the visible and infrared spectral regions.

Solvent effect on the intermolecular proton transfer of the Watson and Crick guanine-cytosine and adenine-thymine base pairs: a polarizable continuum model study.

Herein we present our results on the study of the double proton transfer (DPT) mechanism in the adenine-thymine (AT) and guanine-cytosine (GC) base pairs, both in gas phase and in solution. The latter was modeled using the polarizable continuum method (PCM) in different solvents. According to our DFT calculations, the DPT may occur for both complexes in a stepwise mechanism in condensate phase. In gas phase only the GC base pair exhibits a concerted DPT mechanism. Using the Wigner's tunneling corrections to the transition state theory we demonstrate that such corrections are important for the prediction of the rate constants of both systems in gas and in condensate phase. We also show that (i) as the polarity of the medium decreases the equilibrium constant of the DPT reaction increases in both complexes, and (ii) that the equilibrium constant in the GC complex is four orders of magnitude larger than in AT. This observation suggests that the spontaneous mutations in DNA base pairs are more probable in GC than in AT.

A deep learning based strategy for identifying and associating mitotic activity with gene expression derived risk categories in estrogen receptor positive breast cancers.

The treatment and management of early stage estrogen receptor positive (ER+) breast cancer is hindered by the difficulty in identifying patients who require adjuvant chemotherapy in contrast to those that will respond to hormonal therapy. To distinguish between the more and less aggressive breast tumors, which is a fundamental criterion for the selection of an appropriate treatment plan, Oncotype DX (ODX) and other gene expression tests are typically employed. While informative, these gene expression tests are expensive, tissue destructive, and require specialized facilities. Bloom-Richardson (BR) grade, the common scheme employed in breast cancer grading, has been shown to be correlated with the Oncotype DX risk score. Unfortunately, studies have also shown that the BR grade determined experiences notable inter-observer variability. One of the constituent categories in BR grading is the mitotic index. The goal of this study was to develop a deep learning (DL) classifier to identify mitotic figures from whole slides images of ER+ breast cancer, the hypothesis being that the number of mitoses identified by the DL classifier would correlate with the corresponding Oncotype DX risk categories. The mitosis detector yielded an average F-score of 0.556 in the AMIDA mitosis dataset using a 6-fold validation setup. For a cohort of 174 whole slide images with early stage ER+ breast cancer for which the corresponding Oncotype DX score was available, the distributions of the number of mitoses identified by the DL classifier was found to be significantly different between the high vs low Oncotype DX risk groups (P < 0.01). Comparisons of other risk groups, using both ODX score and histological grade, were also found to present significantly different automated mitoses distributions. Additionally, a support vector machine classifier trained to separate low/high Oncotype DX risk categories using the mitotic count determined by the DL classifier yielded a 83.19% classification accuracy. © 2017 International Society for Advancement of Cytometry.

Increasing Incidence and Prevalence of Multiple Sclerosis in Puerto Rico (2013-2016).

BACKGROUND: The incidence of multiple sclerosis (MS) has been increasing worldwide over the past decades. However, this upward trend has not been examined at the country level in Latin America and the Caribbean (LAC). The aims of this study are to examine trends of MS incidence over 4 years and to provide age- and gender-standardized incidence rate estimates for a Caribbean island. METHODS: Data from the Puerto Rico (PR) MS Foundation's registry was used to identify all newly diagnosed MS cases between 2013 and 2016. MS patients were 18 years and older and met the 2010 revised McDonald criteria. Age- and gender-standardized incidence rates were estimated. RESULTS: A total of 583 new MS cases were diagnosed in PR from 2013 to 2016. The age- and gender-standardized MS incidence rate for PR increased from 6.1/100,000 in 2013 to 6.7/100,000 in 2016. The annual age-standardized MS incidence rates for females rose from 8.4/100,000 in 2013 to 9.8/100,000 in 2016 and were higher than males, which remained around 3.7/100,000. CONCLUSION: Incidence estimates for PR were higher than other LAC countries but consistent with MS increases in other world regions. Our findings tend to rule out several prior potential environmental explanations for high MS incidence rates.

Design and Implementation of a Telepediatric Primary-Level and Low-Cost System to Reduce Unnecessary Patient Transfers.

BACKGROUND: Most inhabitants in Latin America are concentrated in large urban foci with different access to facilities. Although the main hospitals offer specialized services, economically vulnerable populations cannot easily afford these services, the pediatric population being most affected. This article presents the design and implementation of a low cost telepediatric system, applied to primary care hospitals through a study in Bogotá, Colombia, mainly aimed to reduce the number of unnecessary transfers commonly sent to specialized medical services. MATERIALS AND METHODS: The system was carried out over 6 months with a higher incidence of acute respiratory illness in children between 0 and 5 years in nine primary care hospitals in Bogotá. Nineteen (n = 19) pediatricians were trained by a group of engineers that supports the system permanently. The reduction of patient transfers was compared with previous reports of the National Statistical Department in Colombia. RESULTS: The system reduced both the number of patient transfers to higher level hospitals by 83% and the waiting times for patient transfer, improving healthcare in pediatric patients at a reasonable cost, affecting more than 700 patients. At the same time, a decrease of about 17% in the use of antibiotics was observed, which is an important current public health issue. CONCLUSIONS: The use of telemedicine improves the efficiency of public health resources, even in big cities such as Bogotá, reducing the number of unnecessary patient transfers and the optimization and appropriate use of medicines.

Characterizing Architectural Distortion in Mammograms by Linear Saliency.

Architectural distortion (AD) is a common cause of false-negatives in mammograms. This lesion usually consists of a central retraction of the connective tissue and a spiculated pattern radiating from it. This pattern is difficult to detect due the complex superposition of breast tissue. This paper presents a novel AD characterization by representing the linear saliency in mammography Regions of Interest (ROI) as a graph composed of nodes corresponding to locations along the ROI boundary and edges with a weight proportional to the line intensity integrals along the path connecting any pair of nodes. A set of eigenvectors from the adjacency matrix is then used to extract discriminant coefficients that represent those nodes with higher salient lines. A dimensionality reduction is further accomplished by selecting the pair of nodes with major contribution for each of the computed eigenvectors. The set of main salient lines is then assembled as a feature vector that inputs a conventional Support Vector Machine (SVM). Experimental results with two benchmark databases, the mini-MIAS and DDSM databases, demonstrate that the proposed linear saliency domain method (LSD) performs well in terms of accuracy. The approach was evaluated with a set of 246 RoI extracted from the DDSM (123 normal tissues and 123 AD) and a set of 38 ROI from the mini-MIAS collections (19 normal tissues and 19 AD) respectively. The classification results showed respectively for both databases an accuracy rate of 89 % and 87 %, a sensitivity rate of 85 % and 95 %, and a specificity rate of 93 % and 84 %. Likewise, the area under curve (A z ) of the Receiver Operating Characteristic (ROC) curve was 0.93 for both databases.

[Effect of management on tree diversity in secondary vegetation in the Biosphere Reserve of Calakmul, Campeche, Mexico]. / Efecto del manejo sobre la diversidad de árboles en vegetación secundaria en la Reserva de la Biosfera de Calakmul, Campeche, México.

The tropical dry forest (BTS) of Yucatan Peninsula has been managed for centuries, but the relationship between these management efforts and their effects on trees diversity has not been fully understood. The aim of this study was to evaluate the effect of forest management (thinning, harvesting and enrichment of species), in the structure of secondary vegetation derived from dry tropical forests, in two communities in Calakmul, Campeche, Southeast Mexico. We analyzed changes in the composition, species richness, species diversity, and structure in secondary vegetation subject to following types of management: (1) secondary vegetation with beekeeping management (MA), secondary vegetation with forest management (MF), natural secondary vegetation (SM) and tropical dry forest (BTS). The species composition was similar between secondary vegetation managed and unmanaged. On the other hand, between managed secondary vegetation and BTS there were differences in species composition. Species richness was not different between all conditions. MA showed the lowest species diversity and presented higher average density (5 413±770.26 ind.ha-1).MF had lowest average density (3 289 ± 1 183.60 ind.ha-1). BTS showed the highest average basal area (24.89 ± 1.56 m2.ha-1) regarding the other conditions. We concluded that is necessary to keep monitoring the managed areas to detect effects of management that may be adverse or favorable to conservation of floristic diversity of BTS.

Well-Defined Star-Shaped Polyglutamates with Improved Pharmacokinetic Profiles As Excellent Candidates for Biomedical Applications.

There is a need to develop new and innovative polymer carriers to be used as drug delivery systems and/or imaging agents owing to the fact that there is no universal polymeric system that can be used in the treatment of all diseases. Additionally, limitations with existing systems, such as a lack of biodegradability and biocompatibility, inevitably lead to side effects and poor patient compliance. New polymer therapeutics based on amino acids are excellent candidates for drug delivery, as they do not suffer from these limitations. This article reports on a simple yet powerful methodology for the synthesis of 3-arm star-shaped polyglutamic acid with well-defined structures, precise molecular weights (MW), and low polydispersity (D = <1.3). These were synthesized by ring-opening polymerization (ROP) of N-carboxyanhydrides (NCA) in a divergent method from novel multifunctional initiators. Herein, their exhaustive physicochemical characterization is presented. Furthermore, preliminary in vitro evaluation in selected cell models, and exhaustive in vivo biodistribution and pharmacokinetics, highlighted the advantages of these branched systems when compared with their linear counterparts in terms of cell uptake enhancement and prolonged plasma half-life.

An adaptable navigation strategy for Virtual Microscopy from mobile platforms.

Real integration of Virtual Microscopy with the pathologist service workflow requires the design of adaptable strategies for any hospital service to interact with a set of Whole Slide Images. Nowadays, mobile devices have the actual potential of supporting an online pervasive network of specialists working together. However, such devices are still very limited. This article introduces a novel highly adaptable strategy for streaming and visualizing WSI from mobile devices. The presented approach effectively exploits and extends the granularity of the JPEG2000 standard and integrates it with different strategies to achieve a lossless, loosely-coupled, decoder and platform independent implementation, adaptable to any interaction model. The performance was evaluated by two expert pathologists interacting with a set of 20 virtual slides. The method efficiently uses the available device resources: the memory usage did not exceed a 7% of the device capacity while the decoding times were smaller than the 200 ms per Region of Interest, i.e., a window of 256×256 pixels. This model is easily adaptable to other medical imaging scenarios.

Potential polyunsaturated aldehydes in the Strait of Gibraltar under two tidal regimes.

Diatoms, a major component of the large-sized phytoplankton, are able to produce and release polyunsaturated aldehydes after cell disruption (potential PUAs or pPUA). These organisms are dominant in the large phytoplankton fraction (>10 µm) in the Strait of Gibraltar, the only connection between the Mediterranean Sea and the Atlantic Ocean. In this area, the hydrodynamics exerts a strong control on the composition and physiological state of the phytoplankton. This environment offers a great opportunity to analyze and compare the little known distribution of larger sized PUA producers in nature and, moreover, to study how environmental variables could affect the ranges and potential distribution of these compounds. Our results showed that, at both tidal regimes studied (Spring and Neap tides), diatoms in the Strait of Gibraltar are able to produce three aldehydes: Heptadienal, Octadienal and Decadienal, with a significant dominance of Decadienal production. The PUA released by mechanical cell disruption of large-sized collected cells (pPUA) ranged from 0.01 to 12.3 pmol from cells in 1 L, and from 0.1 to 9.8 fmol cell⁻¹. Tidal regime affected the abundance, distribution and the level of physiological stress of diatoms in the Strait. During Spring tides, diatoms were more abundant, usually grouped nearer the coastal basin and showed less physiological stress than during Neap tides. Our results suggest a significant general increase in the pPUA productivity with increasing physiological stress for the cell also significantly associated to low nitrate availability.

Leveraging a realistic synthetic database to learn Shape-from-Shading for estimating the colon depth in colonoscopy images.

Colonoscopy is the choice procedure to diagnose, screening, and treat the colon and rectum cancer, from early detection of small precancerous lesions (polyps), to confirmation of malign masses. However, the high variability of the organ appearance and the complex shape of both the colon wall and structures of interest make this exploration difficult. Learned visuospatial and perceptual abilities mitigate technical limitations in clinical practice by proper estimation of the intestinal depth. This work introduces a novel methodology to estimate colon depth maps in single frames from monocular colonoscopy videos. The generated depth map is inferred from the shading variation of the colon wall with respect to the light source, as learned from a realistic synthetic database. Briefly, a classic convolutional neural network architecture is trained from scratch to estimate the depth map, improving sharp depth estimations in haustral folds and polyps by a custom loss function that minimizes the estimation error in edges and curvatures. The network was trained by a custom synthetic colonoscopy database herein constructed and released, composed of 248400 frames (47 videos), with depth annotations at the level of pixels. This collection comprehends 5 subsets of videos with progressively higher levels of visual complexity. Evaluation of the depth estimation with the synthetic database reached a threshold accuracy of 95.65%, and a mean-RMSE of 0.451cm, while a qualitative assessment with a real database showed consistent depth estimations, visually evaluated by the expert gastroenterologist coauthoring this paper. Finally, the method achieved competitive performance with respect to another state-of-the-art method using a public synthetic database and comparable results in a set of images with other five state-of-the-art methods. Additionally, three-dimensional reconstructions demonstrated useful approximations of the gastrointestinal tract geometry. Code for reproducing the reported results and the dataset are available at https://github.com/Cimalab-unal/ColonDepthEstimation.

Kikuchi-Fujimoto disease type lymph node reaction with increased plasmacytoid dendritic cells may appear as a side effect following COVID-19 vaccination: Report of a case and literature review.

Subsequent to mass vaccination programs against COVID-19, diverse side effects have been described, both at the injection site, such as pain, redness and swelling, and systemic effects such as fatigue, headache, muscle or joint pain. On rare occasions, a lymphadenopathic syndrome may develop, raising the clinical suspicion of a lymphoproliferative disorder. We present the case of a 30-year-old woman who developed self-limiting left axillary lymphadenopathy following COVID-19 vaccination. To date, only seven similar cases with a complete clinicopathological description have been published, and fourteen cases have been notified to the European adverse events databases (Eudravigilance) in relationship with vaccination against COVID-19. It is important to be aware of this potential complication when a lymphadenopathic syndrome develops following vaccination, to avoid unnecessary treatment.

Target engagement of an anti-MT1-MMP antibody for triple-negative breast cancer PET imaging and beta therapy.

PURPOSE: Triple-negative breast cancer (TNBC) is a highly aggressive subtype of breast cancer that lacks effective diagnostic and therapeutic options. Membrane type 1 matrix metalloproteinase (MT1-MMP) is an attractive biomarker for improving patient selection. This study aimed to develop a theranostic tool using a highly tumour-selective anti-MT1-MMP antibody (LEM2/15) radiolabelled with 89Zr for PET and 177Lu for therapy in a TNBC murine model. METHODS: The LEM2/15 antibody and IgG isotype control were radiolabelled with 89Zr. PET imaging was performed in a TNBC orthotopic mouse model at 1, 2, 4, and 7 days after administration. Tissue biodistribution and pharmacokinetic parameters were analysed and Patlak linearisation was used to calculate the influx rate of irreversible uptake. The TNBC mice were treated with [177Lu]Lu-DOTA-LEM2/15 (single- or 3-dose regimen) or saline. Efficacy of [177Lu]Lu-DOTA-LEM2/15 was evaluated as tumour growth and DNA damage (γH2AX) in MDA 231-BrM2-831 tumours. RESULTS: At 7 days post-injection, PET uptake in tumour xenografts revealed a 1.6-fold and 2.4-fold higher tumour-to-blood ratio for [89Zr]Zr-Df-LEM2/15 in the non-blocked group compared to the blocked and IgG isotype control groups, respectively. Specific uptake of LEM2/15 in TBNC tumours mediated by MT1-MMP-binding was demonstrated by the Patlak linearisation method, providing insights into the potential efficacy of LEM2/15-based treatments. A similar uptake was found for [89Zr]Zr-Df-LEM2/15 and [177Lu]Lu-DOTA-LEM2/15 in tumours 7 days post-injection (6.80 ± 1.31 vs. 5.61 ± 0.66 %ID/g). Tumour doubling time was longer in the [177Lu]Lu-DOTA-LEM2/15 3-dose regimen treated group compared to the control (50 vs. 17 days, respectively). The percentage of cells with γH2AX-foci was higher in tumours treated with [177Lu]Lu-DOTA-LEM2/15 3-dose regimen compared to tumours non-treated or treated with [177Lu]Lu-DOTA-LEM2/15 single-dose (12 % vs. 4-5 %). CONCLUSIONS: The results showed that the 89Zr/177Lu-labelled anti-MT1-MMP mAb (LEM2/15) pair facilitated immune-PET imaging and reduced tumour growth in a preclinical TNBC xenograft model.

Climate-driven shifts in decapod larvae assemblages in a temperate estuary.

The study examines the complex impact of climatic patterns, driven by the North Atlantic Oscillation (NAO), on regional climate, hydrology, and sea surface temperatures. Focused on the period from 2003 to 2012, the research specifically investigates the influence of thermal variability on decapod larval communities. Monthly zooplanktonic sampling conducted at the Mondego Estuary, Portugal, entrance over a decade revealed the prevalence of Carcinus maenas, Diogenes pugilator, and Pachigrapsus marmoratus larvae. These assemblages displayed notable interannual and seasonal fluctuations, often corresponding with changes in sea surface temperatures. Significant system shifts around 2007, instigated by the large-scale NAO, led to subsequent modifications in sea surface temperature and decapod larvae communities' dynamics. Post-2007, there was an upward trajectory in both species' abundance and richness. Phenologically during the former period, the community exhibited two abundance peaks, with the earlier peak occurring sooner, attributed to heightened temperatures instead of the unique peak exhibited before 2007. The research further elucidated the occurrences of Marine Heatwaves (MHW) in the region, delving into their temporal progression influenced by the NAO. Although water temperature emerged as a crucial factor influencing decapod larvae communities annually and seasonally, the study did not observe discernible impacts of MHW events on these communities. These communities represent essential trophic links and are crucial for the survival success of adult decapods. Given the rapid pace of climate change and increasing temperatures, it is imperative to assess whether these environmental shifts, particularly in thermal conditions, affect these meroplanktonic communities.

Usefulness of low-cost simulation models to learning surgical techniques for placenta accreta spectrum: An observational educational study.

OBJECTIVE: To evaluate the utility of low-cost simulation models to teach surgical techniques for placenta accreta spectrum (PAS), included in a multimodal education workshop for PAS. METHODS: This was an observational, survey-based study. Participants were surveyed before and after the use of low-fidelity mannequins to simulate two surgical techniques for PAS (one-step conservative surgery [OSCS] and modified subtotal hysterectomy [MSTH]), within a multimodal educational workshop. The workshops included pre-course preparation, didactics, simulated practice of the techniques using low-cost models, and viewing live surgery. RESULTS: Six OSCS/MSTH training workshops occurred across six countries and a total of 270 participants were surveyed. The responses of 127 certified obstetricians and gynecologists (OB-GYNs) were analyzed. Participants expressed favorable impressions of all components of the simulated session. Perceived anatomical simulator fidelity, scenario realism, educational component effectiveness, and self-assessed performance improvement received ratings of 4-5 (positive end of the Likert scale) from over 90% of respondents. When asked about simulation's role in technique comprehension, comfort level in technique performance, and likelihood of recommending this workshop to others, more than 75% of participants rated these aspects with a score of 4-5 (positively) on the five-point scale. CONCLUSION: Low-cost simulation, within a multimodal education strategy, is a well-accepted intervention for teaching surgical techniques for PAS.

Simulation of normal and pathological gaits using a fusion knowledge strategy.

: Gait distortion is the first clinical manifestation of many pathological disorders. Traditionally, the gait laboratory has been the only available tool for supporting both diagnosis and prognosis, but under the limitation that any clinical interpretation depends completely on the physician expertise. This work presents a novel human gait model which fusions two important gait information sources: an estimated Center of Gravity (CoG) trajectory and learned heel paths, by that means allowing to reproduce kinematic normal and pathological patterns. The CoG trajectory is approximated with a physical compass pendulum representation that has been extended by introducing energy accumulator elements between the pendulum ends, thereby emulating the role of the leg joints and obtaining a complete global gait description. Likewise, learned heel paths captured from actual data are learned to improve the performance of the physical model, while the most relevant joint trajectories are estimated using a classical inverse kinematic rule. The model is compared with standard gait patterns, obtaining a correlation coefficient of 0.96. Additionally,themodel simulates neuromuscular diseases like Parkinson (phase 2, 3 and 4) and clinical signs like the Crouch gait, case in which the averaged correlation coefficient is 0.92.