scholarly journals Variable species densities are induced by volume exclusion interactions upon domain growth

2016 ◽  
Author(s):  
Robert J. H. Ross ◽  
C. A. Yates ◽  
R. E. Baker

AbstractIn this work we study the effect of domain growth on spatial correlations in agent populations containing multiple species. This is important as heterogenous cell populations are ubiquitous during the embryonic development of many species. We have previously shown that the long term behaviour of an agent population depends on the way in which domain growth is implemented. We extend this work to show that, depending on the way in which domain growth is implemented, different species dominate in multispecies simulations. Continuum approximations of the lattice-based model that ignore spatial correlations cannot capture this behaviour, while those that explicitly account for spatial correlations can. The results presented here show that the precise mechanism of domain growth can determine the long term behaviour of multispecies populations, and in certain circumstances, establish spatially varying species densities.

2016 ◽  
Author(s):  
Robert J. H. Ross ◽  
R. E. Baker ◽  
C. A. Yates

AbstractDomain growth plays an important role in many biological systems, and so the inclusion of domain growth in models of these biological systems is important to understanding how these biological systems function. In this work we present methods to include the effects of domain growth on the evolution of spatial correlations in a continuum approximation of a lattice-based model of cell motility and proliferation. We show that, depending on the way in which domain growth is implemented, different steady-state densities are predicted for an agent population. Furthermore, we demonstrate that the way in which domain growth is implemented can result in the evolution of the agent density depending on the size of the domain. Continuum approximations that ignore spatial correlations cannot capture these behaviours, while those that account for spatial correlations do. These results will be of interest to researchers in developmental biology, as they suggest that the nature of domain growth can determine the characteristics of cell populations.


2015 ◽  
Vol 2 (3) ◽  
pp. 61-77
Author(s):  
O. Demydenko ◽  
V. Velychko

The contemporary condition of soil cover in Ukraine is characterized. The attention is focused onto widespread degradation processes in soils. The causes that determine the development of these negative processes are considered. The contemporary informational support for the condition of soil cover in Ukraine is estimated. In general, the current available information is of narrow-departmental nature, obtained by different methods and non-correlated monitoring programs. As a rule, it is stored in under-structured databases, incompatible with other information systems; mainly recorded on paper media unusable with modern technologies, whereby such information resources are diffi cult to be compiled together. These disadvantages are strong constraints against consistent usage of materials for evaluation, forecast and management of changes in the soil cover. The Soil Observation program should thereby be combined with Agrochemical Passportization and ecology-ameliora- tive monitoring; in other words, the application of innovative soil-agrochemical methodology is considered. Each individual type of surveys shall complement the others, and taken altogether, they shall constitute a con- sistent Information System, capable of solving the problems of assessing the condition, forecasting, manage- ment, usage and protection of soil resources. The monitoring procedures should be conducted on the basis of a new soil concept in line with unifi ed programs and methods, so as to meet European approaches to the maxi- mum extent. Such a technical composition enables getting information on present-day processes in soils, and is the only combination that actually helps us to “ecologize” our knowledge of soils, which is the leading trend in the scope of global soil-science. Thus obtained results will serve as a State-owned tool which would subse- quently facilitate the use and protection of soil resources all over the country, to be involved in a united global soil-information scope. The attention is focused onto social signifi cance of the information on soils and their fertility in terms of land resources optimization, as well as the formation of sustainable land use in Ukraine. Aim. To demonstrate the long-term effect of different ways of tillage of typical low-humus chernozem on the change in humus content and composition and the direction of transformation processes of organic fertili- zers. To study the changes in the structure of energy reserves in group and fractional composition of humus in typical low-humus light-loamy chernozem of the Forest-Steppe of Ukraine. Methods. Field, laboratory, microbiological, computational, mathematical and statistical. Results. It was determined that in conditions of long-term subsurface tillage the most effi cient humus accumulation occurs in the 0–20 cm layer of chernozem with simultaneous increase in its content in the lower part of the processed layer without any accumulation differentiation. Surface tillage leads to expressed differentiation in humus accumulation in the 0–20 cm layer of soil (0.005 % per year). When 6 t/ha of humus are replaced by 7 t/ha of by-products the intensity of humus accumulation is decreasing regardless of the way of tillage, but humus accumulation was found to be the most effi cient for subsurface tillage. The application of subsurface tillage leads to the increase in the ratio of C HA : C FA , which is conditioned by the increase in the humifi cation of plant remains of by-products in the 0−20 cm layer of soil by 110–112 % – for subsurface tillage, and by 105 % – for surface tillage. Conclusions. It was established that systematic subsurface tillage of typical chernozem of the Left-Bank Forest-Steppe of Ukraine leads to the structuring both of the total reserves of energy С org , and its quality content, aimed at the increase in the intensity of the processes of humifi cation and accumulation of organic carbon, and the decrease in miner- alization. The ratio of energy reserves С org of humic acids to fulvic acids in the 0−30 cm layer of chernozem is 1.85−1.87 regardless of the way of tillage, which testifi es to the repeatability of humus accumulation, but the total reserves of energy С org was higher for subsurface tillage (+ 31 Teracalorie/ha) compared to deep plough- ing. As for the surface tillage, the energy enrichment was at the level of deep ploughing.


Author(s):  
Steven Gunn

Henry VIII fought many wars, against the French and Scots, against rebels in England and the Gaelic lords of Ireland, even against his traditional allies in the Low Countries. But how much did they really affect his subjects? And what role did Henry’s reign play in the long-term transformation of England’s military capabilities? This book searches for the answers to these questions in parish and borough account books, wills and memoirs, buildings and paintings, letters from Henry’s captains, and the notes readers wrote in their printed history books. It looks back from Henry’s reign to that of his grandfather, Edward IV, who in 1475 invaded France in the afterglow of the Hundred Years War, and forwards to that of Henry’s daughter Elizabeth, who was trying by the 1570s to shape a trained militia and a powerful navy to defend England in a Europe increasingly polarized by religion. War, it shows, marked Henry’s England at every turn: in the news and prophecies people discussed, in the money towns and villages spent on armour, guns, fortifications, and warning beacons, in the way noblemen used their power. War disturbed economic life, made men buy weapons and learn how to use them, and shaped people’s attitudes to the king and to national history. War mobilized a high proportion of the English population and conditioned their relationships with the French and Scots, the Welsh and the Irish. War should be recognized as one of the defining features of life in the England of Henry VIII.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A120-A120
Author(s):  
Sashi Kasimsetty ◽  
Himavanth Gatla ◽  
Dhana Chinnasamy

BackgroundMCY-M11, an anti-mesothelin CAR (Meso-CAR) mRNA transfected PBMC cell product manufactured through <1 day-process is under clinical evaluation for the treatment of advanced ovarian cancer and peritoneal mesothelioma. In this in-vitro study, we characterized the phenotypic and functional status of immune cell populations in MCY-M11 and their possible role in antitumor immunity.MethodsMCY-M11 cell product were generated using unmanipulated healthy donor PBMCs (n=5) by transfection of Meso-CAR mRNA using MaxCyte’s proprietary Flow Electroporation® system. Frozen MCY-M11 cell product was thawed and cultured for 18 hours, then co-cultured with hMSLNneg or hMSLNpos human mesothelioma cell line, MSTO-211H, or stimulated with anti-CD3/anti-CD28 antibodies in vitro for 8 days. Distinct cell populations in MCY-M11 were evaluated for kinetics and duration of CAR expression, differentiation, activation, exhaustion, and their ability to secrete various immunomodulatory molecules during in vitro stimulation. Antigen-specific proliferation and cytotoxicity of MCY-M11 against hMSLNpos tumor cells as well as their ability to mount long-term antitumor immunity through epitope spreading mechanisms were studied.ResultsIndividual cell populations in MCY-M11 exhibited a consistent but transient Meso-CAR expression persisting for about 7 days. Cell subsets in MCY-M11 acquired early signs of activation and differentiation within 18–24 hours post-culture, but only attained full activation and lineage-specific differentiation upon specific response to hMSLNpos tumor cells. hMSLN antigen experienced MCY-M11 retained significant fractions of Naïve and Central Memory T cells and increased percentage of Effector Memory T cells along with increased expression of CD62L, CD27, and chemokine receptors (CCR5, CCR7, and CXCR3). MCY-M11 exhibited strong antigen-specific cytotoxicity against hMSLNpos tumor cells with corresponding increase in activation and proliferation of CD4+ and CD8+ T cell subsets and displayed low or no acquisition of known exhaustion markers. NK cells also exhibited a functionally superior molecular signature exhibiting increased levels of NKG2D, NKp44, NKp46, FAS, and TRAIL. The Monocytes and B cells in MCY-M11 also acquired an activated, differentiated, and mature phenotype, expressing molecules required for antigen presentation (HLA-DR, HLA-ABC, and CD205) and T cell co-stimulation (CD80 and CD86) to mount a strong antitumor response. These phenotypic changes in cell subsets of MCY-M11 transpired with simultaneous secretion of potent immunostimulatory molecules and chemokines facilitating an extended antitumor response through epitope spreading.ConclusionsWe demonstrated that MCY-M11 is a unique cell product possessing a complete built-in immune cellular machinery with favorable phenotype and enhanced functions specialized in mediating an effective and long-term antitumor response.Trial RegistrationNCT03608618


2021 ◽  
Vol 22 (12) ◽  
pp. 6313
Author(s):  
Marcelo T. Moura ◽  
Laís B. Latorraca ◽  
Fabíola F. Paula-Lopes

Mammals face environmental stressors throughout their lifespan, which may jeopardize cellular homeostasis. Hence, these organisms have acquired mechanisms to cope with stressors by sensing, repairing the damage, and reallocating resources to increase the odds of long-term survival. Autophagy is a pro-survival lysosome-mediated cytoplasm degradation pathway for organelle and macromolecule recycling. Furthermore, autophagy efflux increases, and this pathway becomes idiosyncratic depending upon developmental and environmental contexts. Mammalian germ cells and preimplantation embryos are attractive models for dissecting autophagy due to their metastable phenotypes during differentiation and exposure to varying environmental cues. The aim of this review is to explore autophagy during mammalian gametogenesis, fertilization and preimplantation embryonic development by contemplating its physiological role during development, under key stressors, and within the scope of assisted reproduction technologies.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Lisanne M. A. Janssen ◽  
Kim van den Akker ◽  
Mohamed A. Boussihmad ◽  
Esther de Vries

Abstract Background Patients with predominantly (primary) antibody deficiencies (PADs) commonly develop recurrent respiratory infections which can lead to bronchiectasis, long-term morbidity and increased mortality. Recognizing symptoms and making a diagnosis is vital to enable timely treatment. Studies on disease presentation have mainly been conducted using medical files rather than direct contact with PAD patients. Our study aims to analyze how patients appraised their symptoms and which factors were involved in a decision to seek medical care. Methods 14 PAD-patients (11 women; median 44, range 16-68 years) were analyzed using semi-structured interviews until saturation of key emergent themes was achieved. Results Being always ill featured in all participant stories. Often from childhood onwards periods of illness were felt to be too numerous, too bad, too long-lasting, or antibiotics were always needed to get better. Recurrent or persistent respiratory infections were the main triggers for patients to seek care. All participants developed an extreme fatigue, described as a feeling of physical and mental exhaustion and thus an extreme burden on daily life that was not solved by taking rest. Despite this, participants tended to normalize their symptoms and carry on with usual activities. Non-immunologists, as well as patients, misattributed the presenting signs and symptoms to common, self-limiting illnesses or other ‘innocent’ explanations. Participants in a way understood the long diagnostic delay. They know that the disease is rare and that doctors have to cover a broad medical area. But they were more critical about the way the doctors communicate with them. They feel that doctors often don’t listen very well to their patients. The participants’ symptoms as well as the interpretation of these symptoms by their social environment and doctors had a major emotional impact on the participants and a negative influence on their future perspectives. Conclusions To timely identify PAD, ‘pattern recognition’ should not only focus on the medical ‘red flags’, but also on less differentiating symptoms, such as ‘being always ill’ and ‘worn out’ and the way patients cope with these problems. And, most important, making time to really listen to the patient remains the key.


2011 ◽  
Vol 35 (5) ◽  
pp. 613-628 ◽  
Author(s):  
Erik Gómez-Baggethun ◽  
Manuel Ruiz-Pérez

In the last decade a growing number of environmental scientists have advocated economic valuation of ecosystem services as a pragmatic short-term strategy to communicate the value of biodiversity in a language that reflects dominant political and economic views. This paper revisits the controversy on economic valuation of ecosystem services in the light of two aspects that are often neglected in ongoing debates. First, the role of the particular institutional setup in which environmental policy and governance is currently embedded in shaping valuation outcomes. Second, the broader economic and sociopolitical processes that have governed the expansion of pricing into previously non-marketed areas of the environment. Our analysis suggests that within the institutional setup and broader sociopolitical processes that have become prominent since the late 1980s economic valuation is likely to pave the way for the commodification of ecosystem services with potentially counterproductive effects in the long term for biodiversity conservation and equity of access to ecosystem services benefits.


1986 ◽  
Vol 164 (3) ◽  
pp. 962-967 ◽  
Author(s):  
M F Luciani ◽  
J F Brunet ◽  
M Suzan ◽  
F Denizot ◽  
P Golstein

At least some long-term in vitro-cultured cytotoxic T cell clones and uncloned cell populations are able, in the presence of Con A, to lyse other cells, to be lysed by other cells, but not to lyse themselves. This as-yet-unexplained result may have implications as to the mechanism of T cell-mediated cytotoxicity.


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