The Redner - Ben-Avraham - Kahng cluster system

We consider a coagulation model first introduced by Redner, Ben-Avraham and Krapivsky in [Redner, Ben-Avraham, Kahng: Kinetics of 'cluster eating', J. Phys. A: Math. Gen., 20 (1987), 1231-1238], the main feature of which is that the reaction between a j-cluster and a k-cluster results in the creation of a |j-k|-cluster, and not, as in Smoluchowski's model, of a (j+k)-cluster. In this paper we prove existence and uniqueness of solutions under reasonably general conditions on the coagulation coefficients, and we also establish differenciability properties and continuous dependence of solutions. Some interesting invariance properties are also proved. Finally, we study the long-time behaviour of solutions, and also present a preliminary analysis of their scaling behaviour.Comment: 24 pages. 2 figures. Dedicated to Carlos Rocha and Luis Magalhaes on the occasion of their sixtieth birthday

The Redner - Ben-Avraham - Kahng coagulation system with constant coefficients: the finite dimensional case

We study the behaviour as $t\to\infty$ of solutions $(c_j(t))$ to the Redner--Ben-Avraham--Kahng coagulation system with positive and compactly supported initial data, rigorously proving and slightly extending results originally established in [4] by means of formal arguments.Comment: 13 pages, 1 figur

The Regulation of Axon Diameter: From Axonal Circumferential Contractility to Activity-Dependent Axon Swelling

In the adult nervous system axon caliber varies widely amongst different tracts. When considering a given axon, its diameter can further fluctuate in space and time, according to processes including the distribution of organelles and activity-dependent mechanisms. In addition, evidence is emerging supporting that in axons circumferential tension/contractility is present. Axonal diameter is generically regarded as being regulated by neurofilaments. When neurofilaments are absent or low, microtubule-dependent mechanisms can also contribute to the regulation of axon caliber. Despite this knowledge, the fine-tune mechanisms controlling diameter and circumferential tension throughout the lifetime of an axon, remain largely elusive. Recent data supports the role of the actin-spectrin-based membrane periodic skeleton and of non-muscle myosin II in the control of axon diameter. However, the cytoskeletal arrangement that underlies circumferential axonal contraction and expansion is still to be discovered. Here, we discuss in a critical viewpoint the existing knowledge on the regulation of axon diameter, with a specific focus on the possible role played by the axonal actin cytoskeleton.This work from the authors’ group was supported by Prémio Melo e Castro—Santa Casa da Misericórdia de Lisboa; by the Infrastructure for NMR, EM and X-rays for Translational Research (iNEXT); and by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the Norte Portugal Regional Operational Programme (NORTE 2020), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project NORTE-01-0145-FEDER-028623. AC and RP-C are funded by Fundação para a Ciência e Tecnologia—FCT (fellowships SFRH/BPD/114912/2016 and SFRH/BD/112112/2015, respectively)

Comparison of biocenoses from sequencing batch and sequencing biofilm batch reactors

Since the extensive research during the 70s, sequencing batch reactors (SBR) have become a quite common modification of activated sludge process. Additionally, the SBR can be combined with biofilm growth on the surface of a support material originating the Sequencing Batch Biofilm Reactors (SBBR). While several comparative studies between the two systems were done in terms of organic carbon and nutrients removal efficiency, a detailed comparison of their biocenoses is not documented in the literature. The present work aims to compare the biocenoses from SBR and SBBR. In order to reach this objective four reactors were operated in parallel. One reactor was operated just with suspended biomass (SBR1) while the others combined suspended biomass with biofilm cultivation. The biofilm was formed on a new type of polyethylene support developed by University of Minho, called DupUM. The bed formed by these supports occupied 5 % (SBBR2), 10 % (SBBR3) and 20 % (SBBR4) of the reactor volume. Microscopic inspection revealed that the quality of biocenoses from reactors started to differ very soon after the inoculation. The biocenose of SBR1 and SBBR2 was dominated by filamentous microorganisms, while in SBBR3 and SBBR4 the communities were clearly more complex. The incorporation of an optimized amount of support for biofilm growth apparently suppressed the overgrowth of filamentous microorganisms. The differences between the biocenoses of the reactors are documented in figure 1

Scaffolds based bone tissue engineering : the role of chitosan

As life expectancy increases, malfunction or loss of tissue caused by injury or disease leads to reduced quality of life in many patients at significant socioeconomic cost. Even though major progress has been made in the field of bone tissue engineering, present therapies, such as bone grafts, still have limitations. Current research on biodegradable polymers is emerging, combining these structures with osteogenic cells, as an alternative to autologous bone grafts. Different types of biodegradable materials have been proposed for the preparation of three-dimensional porous scaffolds for bone tissue engineering. Among them, natural polymers are one of the most attractive options, mainly due to their similarities with extracellular matrix, chemical versatility, good biological performance, and inherent cellular interactions. In this review, special attention is given to chitosan as a biomaterial for bone tissue engineering applications. An extensive literature survey was performed on the preparation of chitosan scaffolds and their in vitro biological performance as well as their potential to facilitate in vivo bone regeneration. The present review also aims to offer the reader a general overview of all components needed to engineer new bone tissue. It gives a brief background on bone biology, followed by an explanation of all components in bone tissue engineering, as well as describing different tissue engineering strategies. Moreover, also discussed are the typical models used to evaluate in vitro functionality of a tissue-engineered construct and in vivo models to assess the potential to regenerate bone tissue are discussed.Fundação para a Ciência e a Tecnologia (FCT

It comes from the sea: macroalgae-derived bioactive compounds with anti-cancer potential

Nature derived compounds represent a valuable source of bioactive molecules with enormous potential. The sea is one of the richest environments, full of skilled organisms, where algae stand out due to their unique characteristics. Marine macroalgae adapt their phenotypic characteristics, such as chemical composition, depending on the environmental conditions where they live. The compounds produced by these organisms show tremendous potential to be used in the biomedical field, due to their antioxidant, anti-inflammatory, immunomodulatory, and anti-cancer properties. Cancer is one of the deadliest diseases in the world, and the lack of effective treatments highlights the urgent need for the development of new therapeutic strategies. This review provides an overview of the current advances regarding the anti-cancer activity of the three major groups of marine macroalgae, i.e., red algae (Rhodophyta), brown algae (Phaeophyceae), and green algae (Chlorophyta) on pancreatic, lung, breast, cervical, colorectal, liver, and gastric cancers as well as leukemia and melanoma. In addition, future perspectives, and limitations regarding this field of work are also discussed.info:eu-repo/semantics/publishedVersio

Improving the Knowledge on Seismogenic Sources in the Lower Tagus Valley for Seismic Hazard Purposes

The Lower Tagus Valley, that includes the metropolitan area of Lisbon, has been struck by several earthquakes which produced significant material damage and loss of lives. Their exact location remains unknown. Our goal is to shed some light into the seismogenic sources in the area using seismic reflection and geological data. In areas with no seismic coverage, potential-field data interpretation was carried out. Seismicity was overlaid to the potential seismogenic structures and high-resolution data was acquired in order to confirm which structures have been active into the Quaternary. Three major fault-zones affecting the Neogene were identified: V. F. Xira, Samora-Alcochete and Pinhal Novo. For the first fault, strong evidences suggest it is active. The other two fault-zones and other structures previously unknown can be correlated with several epicentres. Empirical relationships between maximum moment magnitude and fault area indicate that MW > 6.5 earthquakes can be expected for the larger structures

The new SWOT for a sustainable world

In today’s complex and changing business environment the concern with sustainability has gained more notoriety. However, companies still do not have a sustainable perspective, but a short-term one, where their values are constantly forgotten and this concept is no longer welcomed. This research demonstrates the need for companies to adapt and to start acting in this direction. Following a set of interviews conducted with professionals with management positions of high responsibility, findings reveal that although sustainability is on the management mind, strategies and tools need to be adapted to be at the core of the organization’s strategic formulation. To support this process, a new SWOT analysis to fit a forward-looking sustainable world is proposed. Furthermore, due to the aggregative nature of the model, it represents an essential tool for an open innovation. “SWOT i” integrates the concern with sustainability as one of its pillars, placing the values and impacts that each decision can have at the center of the strategic formulation, allowing their performance to leverage.info:eu-repo/semantics/publishedVersio

Childbirth-related post-traumatic stress disorder symptoms and mother-infant neurophysiological and behavioral co-regulation during dyadic interaction: study protocol

BackgroundMother's childbirth-related posttraumatic stress disorder (PTSD) symptoms have a negative impact on mother and infant's behaviors during dyadic interactions which may increase mother-infant neurophysiological and behavioral co-regulation difficulties, leading to dysregulated mother-infant interactions. This study was specifically designed to analyze: (1) the sociodemographic and obstetric factors associated with mother's childbirth-related PTSD symptoms; (2) mother-infant neurophysiological functioning and behavioral co-regulation during dyadic interaction; (3) the impact of mother's childbirth-related PTSD symptoms on neurophysiological and behavioral mother-infant co-regulation during dyadic interaction; (4) the moderator role of previous trauma on the impact of mother's childbirth-related PTSD symptoms on neurophysiological and behavioral mother-infant co-regulation during dyadic interaction; and (5) the moderator role of comorbid symptoms of anxiety and depression on the impact of mother's childbirth-related PTSD symptoms on neurophysiological and behavioral mother-infant co-regulation during dyadic interaction.MethodsAt least 250 mothers will be contacted in order to account for refusals and dropouts and guarantee at least 100 participating mother-infant dyads with all the assessment waves completed. The study has a longitudinal design with three assessment waves: (1) 1-3 days postpartum, (2) 8 weeks postpartum, and (3) 22 weeks postpartum. Between 1 and 3 days postpartum, mothers will report on-site on their sociodemographic and obstetric characteristics. At 8 weeks postpartum, mothers will complete online self-reported measures of birth trauma, previous trauma, childbirth-related PTSD, anxiety, and depressive symptoms. At 22 weeks postpartum, mothers will complete online self-reported measures of childbirth-related PTSD, anxiety, and depressive symptoms. Mothers and infants will then be home-visited to observe and record their neurophysiological, neuroimaging and behavioral data during dyadic interactions using the Still-face Paradigm. Activation patterns in the prefrontal cortices of mother and infant will be recorded simultaneously using hyperscanning acquisition devices. Unadjusted and adjusted multilevel linear regression models will be performed to analyze objectives 1 to 3. Moderation models will be performed to analyze objectives 4 and 5.DiscussionData from this study will inform psychological interventions targeting mother-infant interaction, co-regulation, and infant development. Moreover, these results can contribute to designing effective screenings to identify mothers at risk of perinatal mental health problems and those who may need specialized perinatal mental health care

Hybrid Deep Modeling of a GS115 (Mut+) Pichia pastoris Culture with State–Space Reduction

JP acknowledges the PhD grant SFRD/BD14610472019, Fundação para a Ciência e Tecnologia (FCT).Hybrid modeling workflows combining machine learning with mechanistic process descriptions are becoming essential tools for bioprocess digitalization. In this study, a hybrid deep modeling method with state–space reduction was developed and showcased with a P. pastoris GS115 Mut+ strain expressing a single-chain antibody fragment (scFv). Deep feedforward neural networks (FFNN) with varying depths were connected in series with bioreactor macroscopic material balance equations. The hybrid model structure was trained with a deep learning technique based on the adaptive moment estimation method (ADAM), semidirect sensitivity equations and stochastic regularization. A state–space reduction method was investigated based on a principal component analysis (PCA) of the cumulative reacted amount. Data of nine fed-batch P. pastoris 50 L cultivations served to validate the method. Hybrid deep models were developed describing process dynamics as a function of critical process parameters (CPPs). The state–space reduction method succeeded to decrease the hybrid model complexity by 60% and to improve the predictive power by 18.5% in relation to the nonreduced version. An exploratory design space analysis showed that the optimization of the feed of methanol and of inorganic elements has the potential to increase the scFv endpoint titer by 30% and 80%, respectively, in relation to the reference condition.publishersversionpublishe