ExpPoint-MAE: Better interpretability and performance for self-supervised point cloud transformers

In this paper we delve into the properties of transformers, attained through self-supervision, in the point cloud domain. Specifically, we evaluate the effectiveness of Masked Autoencoding as a pretraining scheme, and explore Momentum Contrast as an alternative. In our study we investigate the impact of data quantity on the learned features, and uncover similarities in the transformer's behavior across domains. Through comprehensive visualiations, we observe that the transformer learns to attend to semantically meaningful regions, indicating that pretraining leads to a better understanding of the underlying geometry. Moreover, we examine the finetuning process and its effect on the learned representations. Based on that, we devise an unfreezing strategy which consistently outperforms our baseline without introducing any other modifications to the model or the training pipeline, and achieve state-of-the-art results in the classification task among transformer models

Impact of Coated Zinc Oxide Nanoparticles on Photosystem II of Tomato Plants

Zinc oxide nanoparticles (ZnO NPs) have emerged as a prominent tool in agriculture. Since photosynthetic function is a significant measurement of phytotoxicity and an assessment tool prior to large-scale agricultural applications, the impact of engineered irregular-shaped ZnO NPs coated with oleylamine (ZnO@OAm NPs) were tested. The ZnO@OAm NPs (crystalline size 19 nm) were solvothermally prepared in the sole presence of oleylamine (OAm) and evaluated on tomato (Lycopersicon esculentum Mill.) photosystem II (PSII) photochemistry. Foliar-sprayed 15 mg L−1 ZnO@OAm NPs on tomato leaflets increased chlorophyll content that initiated a higher amount of light energy capture, which resulted in about a 20% increased electron transport rate (ETR) and a quantum yield of PSII photochemistry (ΦPSII) at the growth light (GL, 600 μmol photons m−2 s−1). However, the ZnO@OAm NPs caused a malfunction in the oxygen-evolving complex (OEC) of PSII, which resulted in photoinhibition and increased ROS accumulation. The ROS accumulation was due to the decreased photoprotective mechanism of non-photochemical quenching (NPQ) and to the donor-side photoinhibition. Despite ROS accumulation, ZnO@OAm NPs decreased the excess excitation energy of the PSII, indicating improved PSII efficiency. Therefore, synthesized ZnO@OAm NPs can potentially be used as photosynthetic biostimulants for enhancing crop yields after being tested on other plant species

Leaf age-dependent effects of foliar-sprayed CuZn nanoparticles on photosynthetic efficiency and ROS generation in <i>Arabidopsis thaliana</i>

Young and mature leaves of Arabidopsis thaliana were exposed by foliar spray to 30 mg L&minus;1 of CuZn nanoparticles (NPs). The NPs were synthesized by a microwave-assisted polyol process and characterized by dynamic light scattering (DLS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). CuZn NPs effects in Arabidopsis leaves were evaluated by chlorophyll fluorescence imaging analysis that revealed spatiotemporal heterogeneity of the quantum efficiency of PSII photochemistry (&Phi;PS&Iota;&Iota;) and the redox state of the plastoquinone (PQ) pool (qp), measured 30 min, 90 min, 180 min, and 240 min after spraying. Photosystem II (PSII) function in young leaves was observed to be negatively influenced, especially 30 min after spraying, at which point increased H2O2 generation was correlated to the lower oxidized state of the PQ pool. Recovery of young leaves photosynthetic efficiency appeared only after 240 min of NPs spray when also the level of ROS accumulation was similar to control leaves. On the contrary, a beneficial effect on PSII function in mature leaves after 30 min of the CuZn NPs spray was observed, with increased &Phi;PS&Iota;&Iota;, an increased electron transport rate (ETR), decreased singlet oxygen (1O2) formation, and H2O2 production at the same level of control leaves.An explanation for this differential response is suggested

Data-driven competitive facilitative tree interactions and their implications on nature-based solutions

Spatio-temporal data are more ubiquitous and richer than even before and the availability of such data poses great challenges in data analytics. Ecological facilitation, the positive effect of density of individuals on the individual's survival across a stress gradient, is a complex phenomenon. A large number of tree individuals coupled with soil moisture, temperature, and water stress data across a long temporal period were followed. Data-driven analysis in the absence of hypothesis was performed. Information theoretic analysis of multiple statistical models was employed in order to quantify the best data-driven index of vegetation density and spatial scale of interactions. Sequentially, tree survival was quantified as a function of the size of the individual, vegetation density, and time at the optimal spatial interaction scale. Land surface temperature and soil moisture were also statistically explained by tree size, density, and time. Results indicated that in space both facilitation and competition co-exist in the same ecosystem and the sign and magnitude of this depend on the spatial scale. Overall, within the optimal data-driven spatial scale, tree survival was best explained by the interaction between density and year, sifting overall from facilitation to competition through time. However, small sized trees were always facilitated by increased densities, while large sized trees had either negative or no density effects. Tree size was more important predictor than density in survival and this has implications for nature-based solutions: maintaining large tree individuals or planting species that can become large-sized can safeguard against tree-less areas by promoting survival at long time periods through harsh environmental conditions. Large trees had also a significant effect in moderating land surface temperature and this effect was higher than the one of vegetation density on temperature

SHREC’20 Track:Retrieval of digital surfaces with similar geometric reliefs

International audienceThis paper presents the methods that have participated in the SHREC'20 contest on retrieval of surface patches with similar geometric reliefs and 1 the analysis of their performance over the benchmark created for this challenge. The goal of the context is to verify the possibility of retrieving 3D models only based on the reliefs that are present on their surface and to compare methods that are suitable for this task. This problem is related to many real world applications, such as the classification of cultural heritage goods or the analysis of different materials. To address this challenge, it is necessary to characterize the local "geometric pattern" information, possibly forgetting model size and bending. Seven groups participated in this contest and twenty runs were submitted for evaluation. The performances of the methods reveal that good results are achieved with a number of techniques that use different approaches

Cdc6 expression represses E-cadherin transcription and activates adjacent replication origins

The Cdc6 replication licensing factor acts as a molecular switch at the E-cadherin locus, leading to E-cadherin transcriptional repression and local activation of replication

Epidemiological clinical study of recurrent urogenital infections in inpatients and outpatients of Attikon University Hospital

Background/Aim: Bacterial urogenital infections caused by multi-drug resistant organisms (MDROs), are increasingly becoming a severe public health issue. The purpose of the present study was to examine the epidemiology of recurrent UTIs along with antimicrobial resistance patterns in a cohort of patients followed as outpatients at an Infectious Disease clinic of a tertiary care center in Greece. Material and Methods: One hundred, sequential patients suffering from recurrent UTIs and coming for clinical evaluation, follow-up and treatment were examined; microbiological urine culture results were analyzed. Patients were separated into Group A: patients with ≥3 urogenital infections during the last study year, and Group B: patients with ≤2 urogenital infections. Furthermore, antimicrobial resistance patterns and presence of MDROs in relation to the number of urogenital infections during a three years period was evaluated. Results: Group A had a mean of 4.3±1.7 urogenital infections during the last year of the study, while patients in Group B 1.9±0.3 infections over a three years period. An age cut-off of 30 years was critical for higher UTI rates. Escherichia Coli was the predominant isolated pathogen in 96.2% of the patients. Patients with diabetes mellitus had a 3 fold-higher risk for ≥3 UTIs. Resistance to colistin and imipenem was associated with a history of more than 2 episodes of UTIs but observed in a small number of patients with comorbidities. Conclusion: In this pilot study MDRO detection in patients suffering from recurrent UTIs emphasizes the need for continuous epidemiological surveillance in order to improve our understanding of the evolution of resistance in a common community infection as well as to implement successful prevention strategies.Εισαγωγή / Σκοπός: Οι βακτηριακές υποτροπιάζουσες ουρολοιμώξεις που προκαλούνται από ανθεκτικούς σε πολλαπλά φάρμακα οργανισμούς (MDROs) αποτελούν σοβαρό πρόβλημα δημόσιας υγείας. Σκοπός της παρούσας μελέτης ήταν να εξεταστεί η επιδημιολογία των επαναλαμβανόμενων ουρολοιμώξεων και η αντιμικροβιακή αντοχή των απομονούμενων βακτηριακών παθογόνων σε ομάδα εξωτερικών ασθενών τριτοβάθμιου ελληνικού νοσοκομείου. Υλικά και Μέθοδοι: Εξετάστηκαν 100 ασθενείς που πάσχουν από υποτροπιάζουσες UTIs και έρχονταν για κλινική αξιολόγηση, παρακολούθηση και θεραπεία το διάστημα Φεβρουάριος 2015 – Σεπτέμβριος 2018. Έγινε ανάλυση επιδημιολογικών και μικροβιολογικών δεδομένων. Οι ασθενείς χωρίστηκαν στην Ομάδα Α: ασθενείς με ≥3 ουρογεννητικές λοιμώξεις κατά τη διάρκεια του τελευταίου έτους μελέτης και Ομάδα Β: ασθενείς με ≤2 ουρογεννητικές λοιμώξεις. Επιπλέον, αξιολογήθηκαν τα η αντιμικροβιακή αντοχή και η παρουσία των πολυανθεκτικών στελεχών σε σχέση με τον αριθμό των ουρογεννητικών λοιμώξεων κατά τη διάρκεια τριών ετών. Αποτελέσματα: Η ομάδα Α είχε μέση 4.3 ± 1.7 ουρογεννητικές λοιμώξεις κατά τη διάρκεια του τελευταίου έτους της μελέτης, ενώ οι ασθενείς στην ομάδα Β 1.9 ± 0.3. Οι ασθενείς με ηλικία μεγαλύτερη των 30 ετών είχαν στατιστικά σημαντικά υψηλότερα ποσοστά UTIs. Το συχνότερα απομονούμενο παθογόνο ήταν E. coli (96,2% των ασθενών). Οι ασθενείς με σακχαρώδη διαβήτη είχαν 3 φορές μεγαλύτερο κίνδυνο για ≥3 UTIs. Η αντοχή στην κολιστίνη και στην ιμιπενέμη συσχετίστηκαν με ιστορικό περισσότερων από 2 επεισοδίων ουρολοιμώξεων, αλλά αυτό παρατηρήθηκε σε μικρό αριθμό ασθενών (4 ασθενείς) με συννοσηρότητες. Συμπεράσματα: Σε αυτή την πιλοτική μελέτη, η ανίχνευση πολυανθεκτικών παθογόνων στην καλλιέργεια ούρων ασθενών που υποφέρουν από υποτροπιάζουσες ουρολοιμώξεις υπογραμμίζει την ανάγκη για συνεχή επιδημιολογική παρακολούθηση προκειμένου να βελτιωθεί η κατανόησή για την εξέλιξη της αντοχής σε μια συνηθισμένη λοίμωξη της κοινότητας, καθώς και να εφαρμοστούν επιτυχημένες στρατηγικές πρόληψης

Μελέτη της επιδημιολογίας των υποτροπιαζουσών λοιμώξεων ουροποιογεννητικού σε ασθενείς ενδονοσοκομειακούς του Π.Γ.Ν. «Αττικόν» καθώς επίσης και σε όσους προσέρχονται στο εξωτερικό ιατρείο

Εισαγωγή / Σκοπός: Οι βακτηριακές υποτροπιάζουσες ουρολοιμώξεις που προκαλούνται από ανθεκτικούς σε πολλαπλά φάρμακα οργανισμούς (MDROs) αποτελούν σοβαρό πρόβλημα δημόσιας υγείας. Σκοπός της παρούσας μελέτης ήταν να εξεταστεί η επιδημιολογία των επαναλαμβανόμενων ουρολοιμώξεων και η αντιμικροβιακή αντοχή των απομονούμενων βακτηριακών παθογόνων σε ομάδα εξωτερικών ασθενών τριτοβάθμιου ελληνικού νοσοκομείου . Υλικά και Μέθοδοι: Εξετάστηκαν 100 ασθενείς που πάσχουν από υποτροπιάζουσες UTIs και έρχονταν για κλινική αξιολόγηση, παρακολούθηση και θεραπεία το διάστημα Φεβρουάριος 2015 – Σεπτέμβριος 2018. Έγινε ανάλυση επιδημιολογικών και μικροβιολογικών δεδομένων . Οι ασθενείς χωρίστηκαν στην Ομάδα Α: ασθενείς με ≥3 ουρογεννητικές λοιμώξεις κατά τη διάρκεια του τελευταίου έτους μελέτης και Ομάδα Β: ασθενείς με ≤2 ουρογεννητικές λοιμώξεις. Επιπλέον, αξιολογήθηκαν τα ηαντιμικροβιακή αντοχή και η παρουσία των πολυανθεκτικών στελεχώνσε σχέση με τον αριθμό των ουρογεννητικών λοιμώξεων κατά τη διάρκεια τριών ετών. Αποτελέσματα: Η ομάδα Α είχε μέση 4.3 ± 1.7 ουρογεννητικές λοιμώξεις κατά τη διάρκεια του τελευταίου έτους της μελέτης, ενώ οι ασθενείς στην ομάδα Β 1.9 ± 0.3. Οι ασθενείς με ηλικία μεγαλύτερη των 30 ετών είχαν στατιστικά σημα-ντικά υψηλότερα ποσοστά UTIs. Το συχνότερα απομονούμενο παθογόνο ήταν E. coli (96,2% των ασθενών). Οι ασθενείς με σακχαρώδη διαβήτη είχαν 3 φορές μεγαλύτερο κίνδυνο για ≥3 UTIs. Η αντοχή στην κολιστίνη και στην ιμιπενέμη συσχετίστηκαν με ιστορικό περισσότερων από 2 επεισοδίων ουρολοιμώξεων, αλλά αυτό παρατηρήθηκε σε μικρό αριθμό ασθενών (4 ασθενείς) με συννοση-ρότητες. Συμπεράσματα: Σε αυτή την πιλοτική μελέτη, η ανίχνευση πολυανθεκτικών παθογόνων στην καλλιέργεια ούρων ασθενών που υποφέρουν από υποτροπιά-ζουσες ουρολοιμώξεις υπογραμμίζει την ανάγκη για συνεχή επιδημιολογική παρακολούθηση προκειμένου να βελτιωθεί η κατανόησή για την εξέλιξη της αντοχής σε μια συνηθισμένη λοίμωξη της κοινότητας, καθώς και να εφαρμοστούν επιτυχημένες στρατηγικές πρόληψης.Background/Aim: Bacterial urogenital infections caused by multi-drug resistant organisms (MDROs), are increasingly becoming a severe public health issue. The purpose of the present study was to examine the epidemiology of recurrent UTIs along with antimicrobial resistance patterns in a cohort of patients followed as outpatients at an Infectious Disease clinic of a tertiary care center in Greece. Material and Methods: One hundred, sequential patients suffering from recurrent UTIs and coming for clinical evaluation, follow-up and treatment were examined; microbiological urine culture results were analyzed. Patients were separated into Group A: patients with ≥3 urogenital infections during the last study year, and Group B: patients with ≤2 urogenital infections. Furthermore, antimicrobial resistance patterns and presence of MDROs in relation to the number of urogenital infections during a three years period was evaluated. Results: Group A had a mean of 4.3±1.7 urogenital infections during the last year of the study, while patients in Group B 1.9±0.3 infections over a three years period. An age cut-off of 30 years was critical for higher UTI rates. Escherichia Coli was the predominant isolated pathogen in 96.2% of the patients. Patients with diabetes mellitus had a 3 fold-higher risk for ≥3 UTIs. Resistance to colistin and imipenem was associated with a history of more than 2 episodes of UTIs but observed in a small number of patients with comorbidities. Conclusion: In this pilot study MDRO detection in patients suffering from recurrent UTIs emphasizes the need for continuous epidemiological surveillance in order to improve our understanding of the evolution of resistance in a common community infection as well as to implement successful prevention strategies