Genome Size in the Arenaria ciliata Species Complex (Caryophyllaceae), with Special Focus on Northern Europe and the Arctic.

The main aim of the present study has been the completion of genome size data for the diverse arctic-alpine A. ciliata species complex, with special focus on the unexplored arctic taxon A. pseudofrigida, the north-European A. norvegica, and A. gothica from Gotland (Sweden). Altogether, 46 individuals of these three Nordic taxa have been sampled from seven different regions and their genome size estimated using flow cytometry. Three other alpine taxa in the A. ciliata complex (A. multicaulis, A. ciliata subsp. ciliata, and A. ciliata subsp. bernensis) were also collected and analyzed for standardization purposes, comprising 20 individuals from six regions. A mean 2c value of 1.65 pg of DNA was recorded for A. pseudofrigida, 2.80 pg for A. norvegica, and 4.14 pg for A. gothica, as against the reconfirmed 2c value of 1.63 pg DNA for the type taxon A. ciliata subsp. ciliata. Our results presenting the first estimations of genome sizes for the newly sampled taxa, corroborate ploidy levels described in the available literature, with A. pseudofrigida being tetraploid (2n = 4x = 40), A. norvegica possessing predominantly 2n = 8x = 80, and A. gothica with 2n = 10x = 100. The present study also reconfirms genome size and ploidy level estimations published previously for the alpine members of this species complex. Reflecting a likely complex recent biogeographic history, the A. ciliata species group comprises a polyploid arctic-alpine species complex characterized by reticulate evolution, polyploidizations and hybridizations, probably associated with rapid latitudinal and altitudinal migrations in the Pleistocene-Holocene period.

Machine and Deep Learning Approaches Applied to Classify Gougerot-Sjögren Syndrome and Jointly Segment Salivary Glands.

To diagnose Gougerot-Sjögren syndrome (GSS), ultrasound imaging (US) is a promising tool for helping physicians and experts. Our project focuses on the automatic detection of the presence of GSS using US. Ultrasound imaging suffers from a weak signal-to-noise ratio. Therefore, any classification or segmentation task based on these images becomes a difficult challenge. To address these two tasks, we evaluate different approaches: a classification using a machine learning method along with feature extraction based on a set of measurements following the radiomics guidance and a deep-learning-based classification. We propose, therefore, an innovative method to enhance the training of a deep neural network with a two phases: multiple supervision using joint classification and a segmentation implemented as pretraining. We highlight the fact that our learning methods provide segmentation results similar to those performed by human experts. We obtain proficient segmentation results for salivary glands and promising detection results for Gougerot-Sjögren syndrome; we observe maximal accuracy with the model trained in two phases. Our experimental results corroborate the fact that deep learning and radiomics combined with ultrasound imaging can be a promising tool for the above-mentioned problems.

Genome Size in the Arenaria ciliata Species Complex (Caryophyllaceae), with Special Focus on A. ciliata subsp. bernensis, a Narrow Endemic of the Swiss Northern Alps.

The genus Arenaria (Caryophyllaceae) comprises approximately 300 species worldwide; however, to date, just six of these taxa have been investigated in terms of their genome size. The main subject of the present study is the A. ciliata species complex, with special focus on A. ciliata subsp. bernensis, an endemic plant occurring in the Swiss Northern Alps. Altogether, 16 populations and 77 individuals of the A. ciliata complex have been sampled and their genome sizes were estimated using flow cytometry, including A. ciliata subsp. bernensis, A. ciliata s.str., A. multicaulis, and A. gothica. The Arenaria ciliata subsp. bernensis shows the highest 2c-value of 6.91 pg of DNA, while A. gothica showed 2c = 3.69 pg, A. ciliata s.str. 2c = 1.71 pg, and A. multicaulis 2c = 1.57 pg. These results confirm the very high ploidy level of A. ciliata subsp. bernensis (2n = 20x = 200) compared to other taxa in the complex, as detected by our chromosome counting and previously documented by earlier work. The genome size and, thus, also the ploidy level, is stable across the whole distribution area of this taxon. The present study delivers additional support for the taxonomic distinctiveness of the high alpine endemic A. ciliata subsp. bernensis, which strongly aligns with other differences in morphology, phylogeny, phenology, ecology, and plant communities, described previously. In affirming these differences, further support now exists to re-consider the species status of this taxon. Upgrading to full species rank would significantly improve the conservation prospects for this taxon, as, because of its precise ecological adaptation to alpine summit habitats, the A. ciliata subsp. bernensis faces acute threats from accelerated climate warming.

Simultaneous Control and Guidance of an AUV Based on Soft Actor-Critic.

The marine environment is a hostile setting for robotics. It is strongly unstructured, uncertain, and includes many external disturbances that cannot be easily predicted or modeled. In this work, we attempt to control an autonomous underwater vehicle (AUV) to perform a waypoint tracking task, using a machine learning-based controller. There has been great progress in machine learning (in many different domains) in recent years; in the subfield of deep reinforcement learning, several algorithms suitable for the continuous control of dynamical systems have been designed. We implemented the soft actor-critic (SAC) algorithm, an entropy-regularized deep reinforcement learning algorithm that allows fulfilling a learning task and encourages the exploration of the environment simultaneously. We compared a SAC-based controller with a proportional integral derivative (PID) controller on a waypoint tracking task using specific performance metrics. All tests were simulated via the UUV simulator. We applied these two controllers to the RexROV 2, a six degrees of freedom cube-shaped remotely operated underwater Vehicle (ROV) converted in an AUV. We propose several interesting contributions as a result of these tests, such as making the SAC control and guiding the AUV simultaneously, outperforming the PID controller in terms of energy saving, and reducing the amount of information needed by the SAC algorithm inputs. Moreover, our implementation of this controller allows facilitating the transfer towards real-world robots. The code corresponding to this work is available on GitHub.

Mixing particles from various HCV genotypes increases the HBV-HCV vaccine ability to elicit broadly cross-neutralizing antibodies.

The development of a safe, effective and affordable prophylactic vaccine against hepatitis C virus (HCV) remains a medical priority. Hepatitis B-C subviral envelope particles, which could be produced by industrial procedures adapted from those established for the hepatitis B virus vaccine, appear promising for use for this purpose. The prototype HBV-HCV bivalent vaccine-bearing genotype 1a HCV envelopes can induce neutralizing antibodies against this genotype, but is less effective against other genotypes. We show here, in a small animal model, that the use of a set of vaccine particles harbouring envelopes from different HCV genotypes in various association strategies can induce broad neutralizing protection or an optimized protection against a particular genotype prevalent in a given region, such as genotype 4 in Egypt. This vaccine could help to control the hepatitis C epidemic worldwide.

Design and Evaluation of a Wireless Electrocardiogram Monitor in an Operating Room: A Pilot Study.

BACKGROUND: Wired electrocardiogram monitors are an important component of current perioperative monitoring. Wireless monitoring units could help reduce the number of cables attached to patients and thus improve anesthesia ergonomics and patient management. However, there is concern that electromagnetic interference generated by electrosurgical units may prevent effective wireless signals in the operating room. To evaluate the extent of this problem, we developed a Bluetooth electrocardiogram prototype monitor and compared its electrocardiogram traces to those captured with a standard wired electrocardiogram monitor in our operating room. METHODS: Bluetooth electrocardiogram and standard electrocardiogram traces captured from 10 patients undergoing surgical procedures that required use of an electrosurgical unit were compared by analysis of the durations of the P wave, QRS complex, and T wave and the position of the ST segment from the isoelectric line. The impact of the electrosurgical units on the Bluetooth electrocardiogram and S-electrocardiogram recordings was also assessed. RESULTS: There were no clinically relevant differences in P wave, QRS complex, or T-wave durations (0.006, 0.004, and 0.017 seconds, respectively) between Bluetooth electrocardiogram and standard electrocardiogram or in the position of the ST segment from the isoelectric line (0.02 mV). Mean differences were near zero, and Bland-Altman limits of agreement for individual differences were narrow (-0.035 to 0.047, -0.03 to 0.038, and -0.112 to 0.078 seconds for P wave, QRS complex, and T-wave durations, respectively, and -0.13 to 0.17 mV for ST segment position). Electrosurgical units use electrically disrupted Bluetooth electrocardiogram and standard electrocardiogram signals, but there was no electromagnetic interference effect on the Bluetooth electrocardiogram signals. CONCLUSIONS: Wireless electrocardiogram using Bluetooth can be reliably used in the operating room. The electrosurgical unit induces electric rather than electromagnetic artifacts, thus affecting wired and wireless electrocardiogram in a similar fashion.

Role of matrix metalloproteinases in migration and neurotrophic properties of nasal olfactory stem and ensheathing cells.

Adult olfactory ectomesenchymal stem cells (OE-MSCs) and olfactory ensheathing cells (OECs), both from the nasal olfactory lamina propria, display robust regenerative properties when transplanted into the nervous system, but the mechanisms supporting such therapeutic effects remain unknown. Matrix metalloproteinases (MMPs) are an important family of proteinases contributing to cell motility and axonal outgrowth across the extracellular matrix (ECM) in physiological and pathological conditions. In this study, we have characterized for the first time in nasal human OE-MSCs the expression profile of some MMPs currently associated with cell migration and invasiveness. We demonstrate different patterns of expression for MMP-1, MMP-2, MMP-9, and MT1-MMP upon cell migration when compared with nonmigrating cells. Our results establish a correspondence between the localization of these proteinases in the migration front with the ability of cells to migrate. Using various modulators of MMP activity, we also show that at least MMP-2, MMP-9, and MT1-MMP contribute to OE-MSC migration in an in vitro 3D test. Furthermore, we demonstrate under the same conditions of culture used for in vivo transplantation that OE-MSCs and OECs secrete neurotrophic factors that promote neurite outgrowth of cortical and dorsal root ganglia (DRG) neurons, as well as axo-dendritic differentiation of cortical neurons. These effects were abolished by the depletion of MMP-2 and MMP-9 from the culture conditioned media. Altogether, our results provide the first evidence that MMPs may contribute to the therapeutic features of OE-MSCs and OECs through the control of their motility and/or their neurotrophic properties. Our data provide new insight into the mechanisms of neuroregeneration and will contribute to optimization of cell therapy strategies.

Poly(D,L-lactide)-block-poly(2-hydroxyethyl acrylate) block copolymers as potential biomaterials for peripheral nerve repair: in vitro and in vivo degradation studies.

The properties of poly(D,L-lactide)-block-poly(2-hydroxyethyl acrylate) (PLA-b-PHEA) block copolymers by means of in vitro / in vivo (rat) degradation are investigated and compared to those of PLA homopolymer. Over 12 weeks, we observe mass loss and molecular weight decrease. In vitro and in vivo findings are very similar for each polymer tested. When a short PHEA block is used (PLA-b-PHEA 15 000-3 000 g · mol(-1) , 85/15 wt%), the degradation process is found to be very similar to that of homo-PLA, and to be typical of a bulk erosion mechanism, with no mass loss observed until week 7 and continuous decrease of molar mass within this timeframe. For a longer PHEA block length within the block copolymer (PLA-b-PHEA 15 000-7 500 g · mol(-1) , 65/35 wt%), the degradation mechanism is modified, with a significant mass loss observed at early times and only a slight decrease in molar mass. The latter finding is related to the pronounced hydrophilicity and softness of the material induced by the PHEA block, which allow easy diffusion and rapid leakage of the degradation residues from the material towards the aqueous medium. Schwann cells are found to better adhere on spin-coated films of PLA-b-PHEA (85/15 wt%) than on PLA ones. These results show the potential of such hydrophilized PLA-based copolymers for use in peripheral nerve repair.

Convenient access to biocompatible block copolymers from SG1-based aliphatic polyester macro-alkoxyamines.

SG1-based poly(d,l-lactide) (PLA) or poly(epsilon-caprolactone) (PCL) macro-alkoxyamines were synthesized and further used as macroinitiators for nitroxide-mediated polymerization (NMP) of 2-hydroxyethyl (meth)acrylate (HE(M)A) to obtain the corresponding PLA- or PCL-PHE(M)A block copolymers. First, a PLA-SG1 macro-alkoxyamine was prepared by 1,2-intermolecular radical addition (IRA) of the MAMA-SG1 (BlocBuilder) alkoxyamine onto acrylate end-capped PLA previously prepared by ring-opening polymerization. The NMP of HEA monomer from the PLA-SG1 macro-alkoxyamine appeared to be well controlled in the presence of free SG1 nitroxide, contrary to that of HEMA. In the latter case, adjustable molecular weights could be obtained by varying the HEMA to macro-alkoxyamine ratio. The versatility of our approach was then further applied to the preparation of PHEMA-b-PCL-b-PHEMA copolymers from a alpha,omega-di-SG1 functionalized PCL macro-alkoxyamine previously obtained from a PCL diacrylate by IRA. Preliminary studies of neuroblast cultures on these PCL-based copolymer films showed acceptable cyto-compatibility, demonstrating their potential for nerve repair applications.