521,111 results match your criteria dynamics

Sexual Development and the Environment: Conclusions from 40 Years of Theory.

Sex Dev 2021 Jun 15:1-16. Epub 2021 Jun 15.

Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia.

In this review, we consider the insight that has been gained through theoretical examination of environmental sex determination (ESD) and thermolability - how theory has progressed our understanding of the ecological and evolutionary dynamics associated with ESD, the transitional pathways between different modes of sex determination, and the underlying mechanisms. Following decades of theory on the adaptive benefits of ESD, several hypotheses seem promising. These hypotheses focus on the importance of differential fitness (sex-specific effects of temperature on fitness) in generating selection for ESD, but highlight alternative ways differential fitness arises: seasonal impacts on growth, sex-specific ages of maturation, and sex-biased dispersal. Read More

View Article and Full-Text PDF

Temporal order of mutations influences cancer initiation dynamics.

Phys Biol 2021 Jun 15. Epub 2021 Jun 15.

Department of Chemistry and Rice Quantum Institute, Rice University, 6100 Main Street, USA, Houston, Texas, 77005-1892, UNITED STATES.

Cancer is a set of genetic diseases that are driven by mutations. It was recently discovered that the temporal order of genetic mutations affects the cancer evolution and even the nature of the disease itself. The mechanistic origin of these observations, however, remain not well understood. Read More

View Article and Full-Text PDF

Charge-transfer-induced 2D ferromagnetism and realization of thermo-remnant memory effect in ultrathin β-NiOOH-encapsulated graphene.

Nanotechnology 2021 Jun 15. Epub 2021 Jun 15.

Research Center for Spin Dynamics and Spin-Wave Devices, Seoul National University, Seoul 151-744, South Korea, Seoul, Korea (the Republic of).

For graphene-based 2D materials, charge transfer at the interface between graphene and ferromagnetic metal leads to many intriguing phenomena. However, because of the unidirectional spin orientation in ferromagnetic transition metals, interface interaction plays a detrimental role in diminishing the magnetic parameters on 2D surfaces. To overcome this issue, we have synthesized ultrathin 2D weak antiferromagnetic β-NiOOH layers on a graphene surface. Read More

View Article and Full-Text PDF

Seasonal dynamics of biochemical composition and fatty acids of swordfish (Xiphias gladius) in the Southeast Pacific Ocean off the coast of Chile.

Mar Environ Res 2021 Jun 9;169:105388. Epub 2021 Jun 9.

Centro de Investigación en Biodiversidad y Ambientes Sustentables (CIBAS), Universidad Católica de la Santísima Concepción, Concepción, Chile; Departamento de Ecología, Facultad de Ciencias, Universidad Católica de la Santísima Concepción, Casilla 297, Concepción, Chile. Electronic address:

In the Southeast Pacific Ocean, Xiphias gladius migrates through the Chilean coastal zone for feeding. Here, it forages for different prey items from autumn to spring, acquiring a great variety of energy and nutritional reserves. We evaluated seasonal variations in the biochemical reserves (i. Read More

View Article and Full-Text PDF

An improved ultrasonic coda wave method for concrete behavior monitoring under various loading conditions.

Ultrasonics 2021 Jun 8;116:106498. Epub 2021 Jun 8.

College of Automotive and Mechanical Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China.

Monitoring of concrete behavior is an important task to evaluate the safety of concrete structures. This paper proposes a new stretching factor accumulation method based on the stepwise coda wave interference (CWI) to accurately calculate the relative velocity change Δv/v. The Δv/v and residual decorrelation coefficient K are used to study the concrete behavior in step loading experiment and short-time fixed loading experiment. Read More

View Article and Full-Text PDF

Age-dependent modulation of motor network connectivity for skill acquisition, consolidation and interlimb transfer after motor practice.

Clin Neurophysiol 2021 May 8;132(8):1790-1801. Epub 2021 May 8.

University of Groningen, University Medical Center Groningen, Center for Human Movement Sciences, Groningen, the Netherlands; Institute of Sport Sciences and Physical Education, Faculty of Sciences, University of Pécs, Pécs, Hungary; Somogy County Kaposi Mór Teaching Hospital, Kaposvár, Hungary.

Objective: Age-related differences in neural strategies for motor learning are not fully understood. We determined the effects of age on the relationship between motor network connectivity and motor skill acquisition, consolidation, and interlimb transfer using dynamic imaging of coherent sources.

Methods: Healthy younger (n = 24, 18-24 y) and older (n = 24, 65-87 y) adults unilaterally practiced a visuomotor task and resting-state electroencephalographic data was acquired before and after practice as well as at retention. Read More

View Article and Full-Text PDF

Effects of dynamic adsorption on bubble formation and coalescence in partitioned-EDGE devices.

J Colloid Interface Sci 2021 Jun 4;602:316-324. Epub 2021 Jun 4.

Wageningen University, Food Process Engineering Group, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands. Electronic address:

Hypothesis: Dynamic adsorption effects can play a crucial role in bubble formation and stabilization. We hypothesize that microfluidic tools provide direct insights to these effects, and that the final bubble size depends on the intersection of time scales for bubble formation versus adsorption of proteins.

Experiments: We use a microfluidic device to study Laplace pressure-driven formation of bubbles that are stabilized by whey proteins. Read More

View Article and Full-Text PDF

Nanonewton scale adhesion force measurements on biotinylated microbeads with a robotic micropipette.

J Colloid Interface Sci 2021 Jun 3;602:291-299. Epub 2021 Jun 3.

ELTE Eötvös Loránd University, Department of Biological Physics, Budapest, Hungary; CellSorter Company for Innovations, Erdőalja út 174, H-1037 Budapest, Hungary. Electronic address:

Binding force between biomolecules has a crucial role in most biological processes. Receptor-ligand interactions transmit physical forces and signals simultaneously. Previously, we employed a robotic micropipette both in live cell and microbead adhesion studies to explore the adhesion force of biomolecules such as cell surface receptors including specific integrins on immune cells. Read More

View Article and Full-Text PDF

Effect of hyperspectral image-based initial conditions on improving short-term algal simulation of hydrodynamic and water quality models.

J Environ Manage 2021 Jun 12;294:112988. Epub 2021 Jun 12.

School of Civil and Environmental Engineering, Konkuk University, Seoul 05029, Republic of Korea. Electronic address:

Hydrodynamic and water quality modeling have provided valuable simulation results that have enhanced the understanding of the spatial and temporal distribution of algal blooms. Typical model simulations are performed with point-based observational data that are used to configure initial and boundary conditions, and for parameter calibration. However, the application of such conventional modeling approaches is limited due to cost, labor, and time constraints that preclude the retrieval of high-resolution spatial data. Read More

View Article and Full-Text PDF

COVID-19 versus SARS: A comparative review.

J Infect Public Health 2021 Apr 24;14(7):967-977. Epub 2021 Apr 24.

Department of Pathology, Sidra Medicine, Doha, Qatar; Department of Pathology and Laboratory Medicine, Weill Cornell Medicine - Qatar, Doha, Qatar. Electronic address:

The two genetically similar severe acute respiratory syndrome coronaviruses, SARS-CoV-1 and SARS-CoV-2, have each been responsible for global epidemics of vastly different scales. Although both viruses arose from similar origins, they quickly diverged due to differences in their transmission dynamics and spectrum of clinical presentations. The potential involvement of multiple organs systems, including the respiratory, cardiac, gastrointestinal and neurological, during infection necessitates a comprehensive understanding of the clinical pathogenesis of each virus. Read More

View Article and Full-Text PDF

Groundwater bacterial communities evolve over time in response to recharge.

Water Res 2021 May 26;201:117290. Epub 2021 May 26.

Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Germany. Electronic address:

Time series analyses are a crucial tool for uncovering the patterns and processes shaping microbial communities and their functions, especially in aquatic ecosystems. Subsurface aquatic environments are perceived to be more stable than surface oceans and lakes, due to the lack of sunlight, the absence of photosysnthetically-driven primary production, low temperature variations, and oligotrophic conditions. However, periodic groundwater recharge should affect the structure and succession of groundwater microbiomes. Read More

View Article and Full-Text PDF

Metabolic regulation of cardiac regeneration: roles of hypoxia, energy homeostasis, and mitochondrial dynamics.

Curr Opin Genet Dev 2021 Jun 11;70:54-60. Epub 2021 Jun 11.

Laboratory for Heart Regeneration, RIKEN Center for Biosystem Dynamics Research, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0043, Japan. Electronic address:

The adult mammalian heart cannot regenerate after myocardial injury because most cardiomyocytes lack the ability to proliferate. In contrast, cardiomyocytes of vertebrates such as zebrafish and urodele amphibians, but also those of fetal and early neonatal mammals, maintain the ability to proliferate and therefore support regeneration of injured tissue and recovery of cardiac function. Whether evolutionarily conserved regulatory mechanisms of cardiomyocyte proliferation exist and, if so, whether they are modifiable to allow cardiac regeneration in adult mammals are questions of great scientific and medical interest. Read More

View Article and Full-Text PDF

Postprandial dynamics and response of fibroblast growth factor 21 in older adults.

Clin Nutr 2021 Apr 27;40(6):3765-3771. Epub 2021 Apr 27.

German Institute of Human Nutrition, Potsdam-Rehbrücke, Department of Nutrition and Gerontology, Nuthetal, Germany; University of Potsdam, Institute of Nutritional Science, Potsdam, Germany; Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Department of Geriatrics, Berlin, Germany. Electronic address:

Background & Aims: Fibroblast growth factor 21 (FGF21) plays a pivotal role in glucose and lipid metabolism and has been proposed as a longevity hormone. However, elevated plasma FGF21 concentrations are paradoxically associated with mortality in higher age and little is known about the postprandial regulation of FGF21 in older adults. In this parallel group study, we investigated postprandial FGF21 dynamics and response in older (65-85 years) compared to younger (18-35 years) adults following test meals with varying macronutrient composition. Read More

View Article and Full-Text PDF

Telehealth Sustainability in a Neurosurgery Department During the COVID-19 Pandemic.

World Neurosurg 2021 Jun 12. Epub 2021 Jun 12.

Neurosurgery, University of Kentucky, 800 Rose St., Lexington, KY, 40508 USA; Brain Restoration Center, University of Kentucky, 800 Rose St., Lexington, KY, 40508 USA; Neuroscience, University of Kentucky, 800 Rose St., Lexington, KY, 40508 USA. Electronic address:

Background: The pandemic shifted the dynamics of healthcare and neurosurgical practice. Elective surgeries were suspended for 8 weeks in Kentucky. Our objective was to determine if telehealth (TH) visits could be sustained as an alternative to in-person visits. Read More

View Article and Full-Text PDF

Flow Structure and Particle Deposition Analyses for Optimization of a Pressurized Metered Dose Inhaler (pMDI) in a Model of Tracheobronchial Airway.

Eur J Pharm Sci 2021 Jun 12:105911. Epub 2021 Jun 12.

Institute of Lung Biology and Disease, Helmholtz Zentrum Muenchen, Neuherberg 85764, Germany; Comprehensive Pneumology Center, Member of the German Center for Lung Research, Max-Lebsche-Platz 31, Munich 81377, Germany. Electronic address:

Inhalation therapy plays an important role in management or treatment of respiratory diseases such asthma and chronic obstructive pulmonary diseases (COPDs). For decades, pressurized metered dose inhalers (pMDIs) have been the most popular and prescribed drug delivery devices for inhalation therapy. The main objectives of the present computational work are to study flow structure inside a pMDI, as well as transport and deposition of micron-sized particles in a model of human tracheobronchial airways and their dependence on inhalation air flow rate and characteristic pMDI parameters. Read More

View Article and Full-Text PDF

Microglia, synaptic dynamics and forgetting.

Brain Res Bull 2021 Jun 12. Epub 2021 Jun 12.

Center of Stem Cell and Regenerative Medicine, And Department of Neurology of Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310058, China. Electronic address:

Microglia are the major immune cells in the brain parenchyma. Besides their immune functions, microglia are important in regulating the dynamics of synapses. It is believed that the stability of synapses is essential for long-term storage and retrieval of memories, whereas microglial regulation of synaptic dynamics could affect the stability of memories, thus providing a potential mechanism for forgetting. Read More

View Article and Full-Text PDF

Prediction and Boolean logical modelling of synergistic microRNA regulatory networks during reprogramming of male germline pluripotent stem cells.

Biosystems 2021 Jun 12:104453. Epub 2021 Jun 12.

Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Odisha 769008, India. Electronic address:

Unipotent male germline stem (GS) cells can undergo spontaneous reprogramming to germline pluripotent stem (GPS) cells during in vitro culture. In our previous study, we proposed a Boolean logical model of gene regulatory network (GRN) during reprogramming of GS cells to GPS cells. This study was designed to predict and model synergistic microRNA (miRNA) regulatory network during reprogramming of GS cells into GPS cells. Read More

View Article and Full-Text PDF

Developing a simple box-behnken experimental design on the removal of doxorubicin anticancer drug using FeO/graphene nanoribbons adsorbent.

Environ Res 2021 Jun 12:111522. Epub 2021 Jun 12.

Department of Chemical Engineering and Energy, Laboratory of Nanotechnology, Quchan University of Technology, Quchan, Iran.

This paper aims to develop a Box-Behnken experimental design system to optimize the removal process of doxorubicin anticancer drugs. For this goal, FeO/graphene nanoribbons was selected as adsorbent and removal of doxorubicin anticancer drug optimized using Box-Behnken experimental design with a selection of four effective factors. A three-level, four-factor Box-Behnken experimental design was used to assess the relationship between removal percentage as a dependent variable with adsorption weight (0. Read More

View Article and Full-Text PDF

A PGE-MEF2A axis enables context-dependent control of inflammatory gene expression.

Immunity 2021 Jun 9. Epub 2021 Jun 9.

Vita-Salute San Raffaele University, Milan, Italy; San Raffaele Telethon Institute for Gene Therapy (SR-Tiget), Milan, Italy; Genomics of the Innate Immune System Unit, IRCCS San Raffaele Scientific Institute, Milan, Italy. Electronic address:

Tight control of inflammatory gene expression by antagonistic environmental cues is key to ensure immune protection while preventing tissue damage. Prostaglandin E (PGE) modulates macrophage activation during homeostasis and disease, but the underlying mechanisms remain incompletely characterized. Here we dissected the genomic properties of lipopolysaccharide (LPS)-induced genes whose expression is antagonized by PGE. Read More

View Article and Full-Text PDF

Airway basal stem cells reutilize the embryonic proliferation regulator, Tgfβ-Id2 axis, for tissue regeneration.

Dev Cell 2021 Jun 8. Epub 2021 Jun 8.

Laboratory for Lung Development and Regeneration, RIKEN Center for Biosystems Dynamics Research, Kobe 650-0047, Japan. Electronic address:

During development, quiescent airway basal stem cells are derived from proliferative primordial progenitors through the cell-cycle slowdown. In contrast, basal cells contribute to adult tissue regeneration by shifting from slow cycling to proliferating and subsequently back to slow cycling. Although sustained proliferation results in tumorigenesis, the molecular mechanisms regulating these transitions remain unknown. Read More

View Article and Full-Text PDF

Identification and validation of selective deubiquitinase inhibitors.

Cell Chem Biol 2021 Jun 2. Epub 2021 Jun 2.

Department of Cancer Biology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA. Electronic address:

Deubiquitinating enzymes (DUBs) are a class of isopeptidases that regulate ubiquitin dynamics through catalytic cleavage of ubiquitin from protein substrates and ubiquitin precursors. Despite growing interest in DUB biological function and potential as therapeutic targets, few selective small-molecule inhibitors and no approved drugs currently exist. To identify chemical scaffolds targeting specific DUBs and establish a broader framework for future inhibitor development across the gene family, we performed high-throughput screening of a chemically diverse small-molecule library against eight different DUBs, spanning three well-characterized DUB families. Read More

View Article and Full-Text PDF

Global analysis of a cancer model with drug resistance due to Lamarckian induction and microvesicle transfer.

J Theor Biol 2021 Jun 12:110812. Epub 2021 Jun 12.

Bolyai Institute, University of Szeged, Szeged H-6720, Hungary.

Development of resistance to chemotherapy in cancer patients strongly effects the outcome of the treatment. Due to chemotherapeutic agents, resistance can emerge by Darwinian evolution. Besides this, acquired drug resistance may arise via changes in gene expression. Read More

View Article and Full-Text PDF

Fertility decline in sub-Saharan Africa: Does remarriage matter?

Popul Stud (Camb) 2021 Jun 15:1-21. Epub 2021 Jun 15.

Université du Québec à Montréal.

The interplay between remarriage and fertility is among the most poorly documented subjects in sub-Saharan Africa (SSA), despite remarriage being one of the fundamental aspects of marriage dynamics in this region. We use Demographic and Health Survey data from 34 countries in SSA to document the association between remarriage and fertility during the reproductive years and over the fertility transition. The findings show that in 29 countries, remarried women end up having fewer children than women in intact unions, despite attaining similar or higher levels of fertility at early reproductive ages. Read More

View Article and Full-Text PDF

The oldest peracarid crustacean reveals a Late Devonian freshwater colonization by isopod relatives.

Biol Lett 2021 Jun 16;17(6):20210226. Epub 2021 Jun 16.

Department of Taxonomy and Systematics, Naturalis Biodiversity Center, 9517, 2300 RA Leiden, The Netherlands.

Peracarida (e.g. woodlice and side-swimmers) are, together with their sister-group Eucarida (e. Read More

View Article and Full-Text PDF

Immune amnesia induced by measles and its effects on concurrent epidemics.

J R Soc Interface 2021 Jun 16;18(179):20210153. Epub 2021 Jun 16.

Departamento de Electromagnetismo y Física de la Materia, e Instituto Carlos I de Física Teórica y Computacional, Universidad de Granada, E-18071 Granada, Spain.

It has been recently discovered that the measles virus can damage pre-existing immunological memory, destroying B lymphocytes and reducing the diversity of non-specific B cells of the infected host. In particular, this implies that previously acquired immunization from vaccination or direct exposition to other pathogens could be partially erased in a phenomenon named 'immune amnesia', whose effects can become particularly worrisome given the actual rise of anti-vaccination movements. Here, we present the first attempt to incorporate immune amnesia into standard models of epidemic spreading by proposing a simple model for the spreading of two concurrent pathogens causing measles and another generic disease. Read More

View Article and Full-Text PDF

Evolution of an asymptomatic first stage of infection in a heterogeneous population.

J R Soc Interface 2021 Jun 16;18(179):20210175. Epub 2021 Jun 16.

Department of Molecular Biology, Princeton University, Princeton, NJ, USA.

Pathogens evolve different life-history strategies, which depend in part on differences in their host populations. A central feature of hosts is their population structure (e.g. Read More

View Article and Full-Text PDF

Is the diatom sex clock a clock?

J R Soc Interface 2021 Jun 16;18(179):20210146. Epub 2021 Jun 16.

Algorithmic Algebra and Discrete Mathematics, Institute of Mathematics, Faculty of Mathematics and Natural Sciences, University of Kassel, 34109 Kassel, Germany.

The unique life cycle of diatoms with continuous decreasing and restoration of the cell size leads to periodic fluctuations in cell size distribution and has been regarded as a multi-annual clock. To understand the long-term behaviour of a population analytically, generic mathematical models are investigated algebraically and numerically for their capability to describe periodic oscillations. Whereas the generally accepted simple concepts for the proliferation dynamics do not sustain oscillating behaviour owing to broadening of the size distribution, simulations show that a proposed limited lifetime of a newly synthesized cell wall slows down the relaxation towards a time-invariant equilibrium state to the order of a hundred thousand generations. Read More

View Article and Full-Text PDF

An integrated platform to facilitate the calculation, validation and visualization of optical flow velocities in biological images.

J R Soc Interface 2021 Jun 16;18(179):20210248. Epub 2021 Jun 16.

Integrative Sciences and Engineering Programme, NUS Graduate School, National University of Singapore, Singapore.

Optical flow algorithms have seen poor adoption in the biological community compared with particle image velocimetry for quantifying cellular dynamics because of the lack of proper validation and an intuitive user interface. To address these challenges, we present OpFlowLab, an integrated platform that integrates our motion estimation workflow. Using routines in our workflow, we demonstrate that optical flow algorithms are more accurate than PIV in simulated images of the movement of nuclei. Read More

View Article and Full-Text PDF

A dynamic, ensemble learning approach to forecast dengue fever epidemic years in Brazil using weather and population susceptibility cycles.

J R Soc Interface 2021 Jun 16;18(179):20201006. Epub 2021 Jun 16.

Computational Health Informatics Program, Boston Children's Hospital, Boston, MA 02115, USA.

Transmission of dengue fever depends on a complex interplay of human, climate and mosquito dynamics, which often change in time and space. It is well known that its disease dynamics are highly influenced by multiple factors including population susceptibility to infection as well as by microclimates: small-area climatic conditions which create environments favourable for the breeding and survival of mosquitoes. Here, we present a novel machine learning dengue forecasting approach, which, dynamically in time and space, identifies local patterns in weather and population susceptibility to make epidemic predictions at the city level in Brazil, months ahead of the occurrence of disease outbreaks. Read More

View Article and Full-Text PDF

BIO-LGCA: A cellular automaton modelling class for analysing collective cell migration.

PLoS Comput Biol 2021 Jun 15;17(6):e1009066. Epub 2021 Jun 15.

Centre for Information Services and High Performance Computing, Technische Universität Dresden, Dresden, Germany.

Collective dynamics in multicellular systems such as biological organs and tissues plays a key role in biological development, regeneration, and pathological conditions. Collective tissue dynamics-understood as population behaviour arising from the interplay of the constituting discrete cells-can be studied with on- and off-lattice agent-based models. However, classical on-lattice agent-based models, also known as cellular automata, fail to replicate key aspects of collective migration, which is a central instance of collective behaviour in multicellular systems. Read More

View Article and Full-Text PDF