scholarly journals Presence of a resident species aids invader evolution

2020 ◽  
Author(s):  
Josianne Lachapelle ◽  
Elvire Bestion ◽  
Eleanor E Jackson ◽  
C-Elisa Schaum
Keyword(s):  
Small Cell ◽  
Resident Species ◽  
Ostreococcus Tauri ◽  
Extinction Rates ◽  
Invading Species ◽  
Small Cell Size ◽  
Chlamydomonas Moewusii ◽  
Evolutionary Trajectories ◽  
Temperature Preferences ◽  
Ros Tolerance

AbstractPhytoplankton populations are intrinsically large and genetically variable, and interactions between species in these populations shape their physiological and evolutionary responses. Yet, evolutionary responses of microbial organisms in novel environments are investigated almost exclusively through the lens of species colonising new environments on their own, and invasion studies are often of short duration. Although exceptions exist, neither type of study usually measures ecologically relevant traits beyond growth rates. Here, we experimentally evolved populations of fresh- and seawater phytoplankton as monocultures (the green algae Chlamydomonas moewusii and Ostreococcus tauri, each colonising a novel, unoccupied salinity) and co-cultures (invading a novel salinity occupied by a resident species) for 200 generations. Colonisers and invaders differed in extinction risks, phenotypes (e.g. size, primary production rates) and strength of local adaptation: invaders had systematically lower extinction rates and broader salinity and temperature preferences than colonisers – regardless of the environment that the invader originated from. We emphasise that the presence of a locally adapted species has the potential to alter the invading species’ eco-evolutionary trajectories in a replicable way across environments of differing quality, and that the evolution of small cell size and high ROS tolerance may explain high invader fitness. To predict phytoplankton responses in a changing world, such interspecific relationships need to be accounted for.

scholarly journals Analysis of the type material of Gomphosphenia tackei (Bacillariophyceae) and comparison to epizoic diatom populations on freshwater snails

2021 ◽  
Vol 154 (2) ◽  
pp. 257-263
Author(s):  
Mateusz Rybak ◽  
Łukasz Peszek ◽  
Anita Poradowska
Keyword(s):  
Electron Microscopy ◽  
Lymnaea Stagnalis ◽  
Morphological Characteristics ◽  
Small Cell ◽  
Type Material ◽  
Freshwater Snails ◽  
Sem Images ◽  
Small Cell Size ◽  
Type Population ◽  
Scanning Electron

Background and aims – Hustedt (1942) originally described Gomphosphenia tackei from Germany under the name Gomphonema tackei. Because of the small cell size and the lack of scanning electron microscopy (SEM) images from the type material, it is often confused with other species from this genus, especially with G. stoermeri. The aim of this paper was to present detailed morphological characteristics of G. tackei based on the analysis of the type material and of several epizoic populations from Central Europe. Material and methods – The material in this study was collected from the shells of the freshwater snails Lymnaea stagnalis, Planorbarius corneus, and Planorbis planorbis. Additionally, for an unambiguous species identification, the type material for Gomphosphenia tackei was analyzed using light and scanning electron microscopes.Key results – The presence of Gomphosphenia tackei was confirmed in the studied material. The largest population (up to 19%) was recorded on the shell surfaces of living snails, whereas on empty shells, the diatom did not seem to be present or only in very low numbers. Valves are typically clavate with rounded apices. Valves are frequently observed in girdle view, often joint together in pairs. The valves in the studied populations had a valve length of 7–29 µm, a valve width of 3–4 µm, and a stria density of 25–29 striae in 10 µm. In the type population, valve length ranged from 7.5 to 27 µm with a valve width of 3.0–4.0 µm and a stria density of 23–29 striae per 10 µm. Striae were composed of 2–4 elongated to rounded areolae per stria. At the apices, the striae were composed of one single areola. The cells were attached to the substratum by their footpole.Conclusion – Published illustrations of Gomphosphenia tackei do not always correctly represent this species. Individual cells are attached to the substratum by secreted mucilage, probably via their areolae or girdle band pores located on the footpole.

Morphologies of Low-Density Cellular Materials

MRS Bulletin ◽  
1990 ◽  
Vol 15 (12) ◽  
pp. 21-23
Keyword(s):  
Spatial Scale ◽  
Cell Size ◽  
Cellular Materials ◽  
Small Cell ◽  
Low Density ◽  
Foam Structure ◽  
Standard Nomenclature ◽  
Small Cell Size ◽  
Simple Models

This section will provide a background for understanding and visualizing the microstructures observed in LDMMs. The word microcellular means small cell size, or more generally (because most low-density materials are not composed of easily recognizable “cells”) some measure of the spatial scale of the foam structure. The concept, measurement, and significance of cell size is intrinsically connected to the morphology, as are certain properties (e.g., stiffness). These matters are covered in later sections. As a background, this article describes some of the structural morphologies of low-density foams, not all of them available as LDMMs (i.e., simultaneously low-density and microcellular.) Interested readers are encouraged to also examine References 1 and 2 because a detailed discussion would take us too far afield. Instead, we shall indicate how most low-density morphologies may be considered in terms of a few simple models of morphological types encountered and how they arise. Often these are seen most cleanly in large-celled foams. Note that these are simplifications—there is no standard nomenclature.

Prediction of neoadjuvant chemotherapeutic efficacy by CTC and cfDNA in patients with locally advanced breast cancer.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. 551-551
Author(s):  
Ge Ma ◽  
Jingyi Wang ◽  
Xiaoan Liu ◽  
Tiansong Xia ◽  
Shui Wang
Keyword(s):  
Breast Cancer ◽  
Advanced Breast Cancer ◽  
Cell Size ◽  
Locally Advanced Breast Cancer ◽  
Locally Advanced ◽  
Roc Curves ◽  
Small Cell ◽  
Advanced Breast ◽  
Dna Integrity ◽  
Small Cell Size

551 Background: Neoadjuvant chemotherapy (NCT) is the standard treatment for patients with locally advanced breast cancer (LABC). Liquid biopsy, including circulating tumor cells (CTCs) and cell free DNA (cfDNA) represent an important paradigm shift in precision medicine. The aim of this study was to estimate the value of CTCs and cfDNA in efficacy prediction of the response to NCT in patients with LABC. Methods: Patients with LABC received EC4-T4 regimen NCT. CTCs and cfDNA obtained at time of biopsy, after first course of NCT and after the last course of NCT. All patients were divided into two groups according to pathological reactivity. A novel SE-iFISH strategy, improved for detection of CTCs, was applied. CTCs(CD45-/CD31-) with different cytogenetic abnormality of aneuploid chromosome 8 and small cell size CTCs (≤5 mm of WBCs) were analyzed separately in LABC patients subjected to NCT for the first time. Plasma DNA biomarkers ALU 111 and ALU 260 elements were evaluated using qRT-PCR. DNA integrity was calculated relative to the breast cancer cell line MCF-7. Clinical significance of diverse subtypes of CTCs and cfDNA was systematically investigated. Results: A total of 45 patients was enrolled in this study. According to the therapy response, 6/45 patients had high response (High-R) and 39/45 patients had low response (Low-R). There were no significant differences in CTC number and small cell size CTC number between High-R and Low-R groups in all three detections. However, the CTC number kept stable in the High-R group, but increased continually during NCT in Low-R group. In 45 patients, the percentage of CTCs with trisomy 8, which were related to cancer metastasis, incresed in the Low-R group at the third dectection. The concentration of cfDNA in all three detections did not indicate outcome of NCT. However, concentration of ALU 111 increased in Low-R patients during NCT. In High-R patients, no significant increase was observed. A CTC and cfDNA panel were constructed to discriminate High-R patients from Low-R patients. The areas under the receiver-operating characteristic (ROC) curves of the pannel for the three times were 0.803, 0.859 and 0.667, respectively. DNA integrity index(CFDI) was significantly higher in High-R group than Low-R after first course of NCT. The areas under the ROC curves of the CFDI for the three times were 0.675, 0.863 and 0.697, respectively. Conclusions: The trend of cfDNA concentration changed resembled to the number of CTCs, small cell size CTCs and triploid CTCs during NCT, and could predict tumor response to ongoing treatment.

scholarly journals The tiny eukaryote Ostreococcus provides genomic insights into the paradox of plankton speciation

2007 ◽  
Vol 104 (18) ◽  
pp. 7705-7710 ◽  
Author(s):  
Brian Palenik ◽  
Jane Grimwood ◽  
Andrea Aerts ◽  
Pierre Rouzé ◽  
Asaf Salamov ◽  
...  
Keyword(s):  
Fusion Proteins ◽  
Surface Characteristics ◽  
Marine Phytoplankton ◽  
Major Protein ◽  
Ostreococcus Tauri ◽  
New Genes ◽  
Small Cell Size ◽  
Catalytically Active ◽  
Paradox Of Plankton ◽  
Ostreococcus Lucimarinus

The smallest known eukaryotes, at ≈1-μm diameter, are Ostreococcus tauri and related species of marine phytoplankton. The genome of Ostreococcus lucimarinus has been completed and compared with that of O. tauri. This comparison reveals surprising differences across orthologous chromosomes in the two species from highly syntenic chromosomes in most cases to chromosomes with almost no similarity. Species divergence in these phytoplankton is occurring through multiple mechanisms acting differently on different chromosomes and likely including acquisition of new genes through horizontal gene transfer. We speculate that this latter process may be involved in altering the cell-surface characteristics of each species. In addition, the genome of O. lucimarinus provides insights into the unique metal metabolism of these organisms, which are predicted to have a large number of selenocysteine-containing proteins. Selenoenzymes are more catalytically active than similar enzymes lacking selenium, and thus the cell may require less of that protein. As reported here, selenoenzymes, novel fusion proteins, and loss of some major protein families including ones associated with chromatin are likely important adaptations for achieving a small cell size.

The Silicon Pixel Sensors in ATLAS

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1100-1102 ◽  
Author(s):  
◽  
IGOR GOLELOV
Keyword(s):  
Collection Efficiency ◽  
Signal To Noise Ratio ◽  
Small Cell ◽  
Pixel Detector ◽  
Signal To Noise ◽  
Charge Collection Efficiency ◽  
Atlas Experiment ◽  
Pixel Sensors ◽  
Small Cell Size ◽  
Good Signal

The ATLAS experiment is now in the process of finalizing the development of the design of silicon pixel sensors for use in the pixel detector. The sensors will be operated in a severe LHC radiation enviroment with bias voltages at the end of lifetime up to 600 V while maintaining a good signal-to-noise ratio and charge collection efficiency, small cell size and minimal multiple scattering. The radiation hardness issues and quality assurance procedures are discussed.

scholarly journals New high order FDTD method to solve EMC problems

2015 ◽  
Vol 4 (2) ◽  
pp. 17 ◽  
Author(s):  
N. Deymier ◽  
T. Volpert ◽  
X. Ferrieres ◽  
V. Mouysset ◽  
B. Pecqueux
Keyword(s):  
Electromagnetic Compatibility ◽  
Numerical Approximation ◽  
Fdtd Method ◽  
Higher Order ◽  
Small Cell ◽  
Small Cell Size ◽  
Dg Method ◽  
The Time Domain ◽  
Spatial Approximation ◽  
The Cost

In electromagnetic compatibility (EMC) context, we are interested in developing new ac- curate methods to solve efficiently and accurately Maxwell’s equations in the time domain. Indeed, usual methods such as FDTD or FVTD present im- portant dissipative and/or dispersive errors which prevent to obtain a good numerical approximation of the physical solution for a given industrial scene unless we use a mesh with a very small cell size. To avoid this problem, schemes like the Discontinuous Galerkin (DG) method, based on higher order spa- tial approximations, have been introduced and stud- ied on unstructured meshes. However the cost of this kind of method can become prohibitive accord- ing to the mesh used. In this paper, we first present a higher order spatial approximation method on carte- sian meshes. It is based on a finite element ap- proach and recovers at the order 1 the well-known Yee’s schema. Next, to deal with EMC problem, a non-oriented thin wire formalism is proposed for this method. Finally, several examples are given to present the benefits of this new method by compar- ison with both Yee’s schema and DG approaches.

scholarly journals APLIKASI MIKROFOTOGRAFI UNTUK MENGEKSPLORASI JENIS-JENIS CYANOPHYTA

2014 ◽  
Vol 1 (2) ◽  
Author(s):  
Widodo Widodo
Keyword(s):  
Microscopic Observation ◽  
Light Microscope ◽  
Size Range ◽  
Digital Camera ◽  
Small Cell ◽  
Eukaryotic Cells ◽  
Plant Systematics ◽  
Microscopy Observation ◽  
Small Cell Size ◽  
Preparation Techniques

Archiving and dissemination of data , techniques, and observations of Cyanophyta required for optimization of succesfully low plant systematics studies. This paper aims to present the preparation techniques and the results of Cyanophyta algae observing with light microscope and digitaly camera. Sources accurate specimen was also informed by the author repeatedly experience in organizing learning plant systematics. Preparation and microscopic observation Cyanophyta consists of preparation of accurate source of specimens , microscopic observation to obtain optimum picture of the object and focus , shooting or recording images using a digital camera. The image files are stored and are equipped with a scale.Results of preparation , observation and shooting showed that cells and colonies all Cyanophyta (Oscillatoria , Anabaena , Nostoc ) has a similar size range that requires preparation to optimize the use of the same light microscop . Cells of Cyanophyta colonies can be seen clearly in the eyepiece magnification of 10x and 40x objective. Less than that magnification, The thalus of Cyanophyta difficult to observe because of the relatively small cell size compared to the size of eukaryotic cells. By shooting with digitaly camera, microscopy observation images can be captured as digital specimen. Observing the digitaly specimen does not change depending on season and time. The digital images can also be analyzed and studied further.

Electron Microscopy of Stress-Induced Structural Alterations Near Inclusions in Bearing Steels

1966 ◽  
Vol 88 (3) ◽  
pp. 568-571 ◽  
Author(s):  
John L. O’Brien ◽  
Alwyn H. King
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Nonmetallic Inclusions ◽  
Cell Formation ◽  
Small Cell ◽  
Structural Alterations ◽  
Bearing Steels ◽  
Thin Foils ◽  
Transmission Electron ◽  
Small Cell Size

The white-etching structural alteration occurring around nonmetallic inclusions in cyclically stressed bearing steels has been studied by transmission-electron microscopy. In order to use this method, thin foils have been prepared with an edge running through the alteration. It has been found that the alteration is due to the formation of 0.05 to 0.1-micron cells in ferrite. The cell formation is similar to that seen in fatigued iron except for the small cell size of the deformed steel. Evidence is also given that deformation causes breakup of the carbides produced on the tempering of steel prior to deformation.

scholarly journals Small Cell Size Circulating Aneuploid Cells as a Biomarker of Prognosis in Resectable Non-Small Cell Lung Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Yang Hong ◽  
Jiahui Si ◽  
Jie Zhang ◽  
Ying Xiong ◽  
Jianzhi Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cell Size ◽  
Cell Lung Cancer ◽  
Large Cell ◽  
Small Cell ◽  
Chromosome 8 ◽  
Small Cell Lung ◽  
Post Surgery ◽  
Small Cell Size

ObjectiveThe size distribution of circulating aneuploid cells (CACs) and its clinical significance were investigated in resectable non-small cell lung cancer (NSCLC).Patients and MethodsA total of 50 patients with resectable NSCLC were enrolled in this study. Blood samples (50 pre-surgery and 35 post-surgery) were collected and used for the detection of CAC chromosome 8 heteroploidy through the subtraction enrichment and immunostaining fluorescence in situ hybridization (SE-iFISH) method.ResultsLess than 20% small cell size and more than 80% large cell size CACs were detected. Karyotypes, including triploid, tetraploid, and multiploid, had varying distributions. The triploid subtype accounted for the majority of small cell size CACs, whereas the multiploid subtype accounted for the majority of large cell size CACs. We found that total small cell size and triploid small cell size CACs, but not large cell size CACs, derived from pre-surgery samples, were associated with shorter disease-free survival. Moreover, total small cell size and triploid small cell size CACs were associated with higher TNM stage and recurrence. Nevertheless, the variation between pre- and post-surgery CACs was not related to survival among patients with resectable NSCLC.ConclusionsPre-surgery small cell size CACs, especially the triploid subtype, could be regarded as a potential prognostic biomarker for patients with resectable NSCLC.

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