scholarly journals Morphological Study of Bacillus thuringiensis Crystals and Spores

2020 ◽  
Vol 11 (1) ◽  
pp. 155
Author(s):  
Hadi Loutfi ◽  
Nancy Fayad ◽  
Fabrice Pellen ◽  
Bernard Le Jeune ◽  
Maissa Chakroun ◽  
...  

In this paper, we report a morphological study of the crystals and spores of different shapes synthesized by seven different strains of Bacillus thuringiensis. Crystals and spores were separated after 48 h of culture on T3 agar medium and imaged under a scanning electron microscope (SEM). Sizes of the crystals and spores were determined using Image J software. The results showed that crystal and spore sizes were normally distributed. In addition, the volumes and aspect ratios of the crystals and spores were calculated. The statistical analysis of the data showed the variability of the size distribution and morphological data of the crystals produced by the analyzed strains. Furthermore, variations in spore size and shape within the same serovar were observed, indicating that, perhaps, there are still some unexplored differences between strains of this serovar, making them less identical than what was believed so far.

Author(s):  
Susan B.G. Debaene ◽  
John S. Gardner ◽  
Phil S. Allen

The coleorhiza is a nonvascular sheath that encloses the embryonic radicle in Poaceae, and is generally the first tissue to emerge during germination. Delicate hairlike extensions develop from some coleorhiza cells prior to radicle emergence. Similar to root hairs, coleorhiza hairs are extremely sensitive to desiccation and are damaged by exposure to negative water potentials. The coleorhiza of Lolium perenne is somewhat spherical when first visible, after which a knob forms at a right angle to the caryopsis due to inner pressure from the elongating radicle. This knob increases in length until the radicle finally punctures the coleorhiza. Standard fixation procedures cause severe desiccation of coleorhiza cells and hairs, making morphological study of the coleorhiza difficult. This study was conducted to determine a more successful process for coleorhiza preservation.


Zootaxa ◽  
2018 ◽  
Vol 4434 (1) ◽  
pp. 111
Author(s):  
JOSÉ G. PALACIOS-VARGAS ◽  
AILA SOARES FERREIRA ◽  
DOUGLAS ZEPPELINI

A new diagnosis of Denisiella is provided, based on the revision of most descriptions, including three new species from Brazil. New Brazilian taxa share the presence of 6 + 6 eyes, 4 + 4 serrate spine-like on tibiotarsi III and the polycarinate setae on tibiotarsi II but differ from each other by the shape and size of the sensilla of the tibiotarsi I. Denisiella rhizophorae sp. nov. has the combination of sensilla on tibiotarsi I of rhagidial type and C2 blunt on antennal segment III. Only D. betschi sp. nov. has barbulate spines on head and D. caatingae sp. nov. is the only which males present nasal organ. They are illustrated with drawings and scanning electron microscope photographs. Three different shapes of sensilla in the tibiotarsi I were observed and were compared with other species. 


2015 ◽  
Vol 723 ◽  
pp. 544-547
Author(s):  
Xiang Wei Cheng ◽  
Da Jin Xiong ◽  
Chao Huo

Using intermittent bubbling carbonation method to prepare nanoCaCO3, the effect of crystal orientation agents on the morphology of nanoCaCO3 was studied. The nanoCaCO3 was characterized by means of field emission scanning electron microscope (FE-SEM), X-ray diffraction (XRD), Laser particle analyzer. The results showed that the different shapes nanoCaCO3 was synthesized by adding different crystal orientation agents to control the shape of the product. The as-prepared CaCO3 were pure calcite crystal and the average particle sizes were within the range of 25.7 to 60.9 nm.


2013 ◽  
Vol 28 (S2) ◽  
pp. S315-S326 ◽  
Author(s):  
Ravinder Singh Joshi ◽  
Harpreet Singh

In present investigation, effect of modulation and machining parameters on deformation level of the chips produced during modulation assisted machining (MAM) has been studied. It is shown that disruption in tool-chip contact during modulation assisted machining helps in the formation of discrete chips. Size and shape of the particles produced in MAM can be controlled by varying modulation and machining conditions. Particulates of different shapes and sizes ranging from 100 µm to 5 mm with an aspect ratio of ~10 were produced using MAM. The morphology of the particulates produced was characterized by scanning electron microscope (SEM). Deformation in chip particulates was investigated using X-Ray diffraction. The crystallite size and internal strain in particulates were evaluated using Scherrer and Williamson-Hall methods respectively. The crystallite size of the particulates was found to decrease with decrease in their size, whereas internal strain in particulates was observed to increase with decrease in their size. Furthermore, the length of particulates was observed to decrease with an increase in the ratio of frequency of modulation (fm) to frequency of workpiece rotation (fw). However, the corresponding change in microstrain and crystallite size was insignificant with change in this ratio.


2019 ◽  
Vol 9 (9) ◽  
pp. 1901 ◽  
Author(s):  
Federica Vurchio ◽  
Pietro Ursi ◽  
Francesco Orsini ◽  
Andrea Scorza ◽  
Rocco Crescenzi ◽  
...  

Micro Electro Mechanical Systems (MEMS)-Technology based micro mechanisms usually operate within a protected or encapsulated space and, before that, they are fabricated and analyzed within one Scanning Electron Microscope (SEM) vacuum specimen chamber. However, a surgical scenario is much more aggressive and requires several higher abilities in the microsystem, such as the capability of operating within a liquid or wet environment, accuracy, reliability and sophisticated packaging. Unfortunately, testing and characterizing MEMS experimentally without fundamental support of a SEM is rather challenging. This paper shows that in spite of large difficulties due to well-known physical limits, the optical microscope is still able to play an important role in MEMS characterization at room conditions. This outcome is supported by the statistical analysis of two series of measurements, obtained by a light trinocular microscope and a profilometer, respectively.


2016 ◽  
Vol 1133 ◽  
pp. 175-179
Author(s):  
Azlinda Abdul Ghani ◽  
Ragunathan Santiagoo ◽  
Tunku Alisha Zanariah Tunku Ozir ◽  
Sam Sung Ting ◽  
Hanafi Ismail

Polypropylene (PP)/ recycled acrylonitrile butadiene rubber (NBRr)/ banana skin powder (BSP) composites were studied. Different BSP filer loading (5, 10, 15,20,25,30 wt. %) were prepared by using heated two roll mill at 180 °C. Then, the composites were tested for functional group using FTIR model Perkin Elmer Series 2. Field Emission Scanning Electron Microscope (VPFESEM) model Zeiss SUPRA 35VP also were using for morphological study. The effect of 3-aminopropyltrimethoxysilane (APS) as coupling agent were evaluated.The FTIR test shows different bands around 3200-3500 and 1740 cm-1 which represent the stretching of OH and C=O groups respectively. As for BSP which composed mostly of cellulose, hemicelluloses and lignin, the cellulose backbone C-OH is represent by the peaks of 1050 and 1048 cm-1 respectively. The γ-APS intense band around 1167 cm-1 and 1098 cm-1 in treated composite was assigned to the stretching of the-Si-O-Cellulose and –Si-O-Si-bond respectively. The large band around 1050 cm-1 found on BSP filler was attribute to the –Si-OH group which later this band will disappear after the surface modification. This evidenced that bonding between γ-APS treated BSP with PP/NBRr matrices. Morphological study supported this finding which BSP filler treated with γ-APS has improved the adhesion between BSP filler and PP/NBRr matrices.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Alessandra Gavazza ◽  
Marianna Ricci ◽  
Martina Brettoni ◽  
Biancaurora Gugliucci ◽  
Anna Pasquini ◽  
...  

The presence of unusual two RBCs patterns (so-called “quatrefoil RBCs,” qRBCs) on canine blood smears at Optical Microscope (OM) was seen during routine evaluation of CBCs. Two consecutive retrospective investigations were arranged including about 7,000 CBCs and clinical records and laboratory data from dogs showing qRBCs. Few samples with qRBCs were prepared for Scanning Electron Microscope (SEM). qRBCs were found in 6.89% (139 of 2016) and 8.47% (133 of 1569) of dogs and in 3.89% (154 of 3,958) and 4.47% (138 of 3,081) of CBCs (some dogs were tested more than once). Statistical analysis was significant for age groups (Chi squared,P<0.0001), decreased total leukocyte and neutrophil counts (ANOVA,P<0.0001), RBCs anisocytosis, polychromasia, and Howell-Jolly bodies (ANOVA,P<0.018, <0.005, and <0.003, respectively). qRBCs were distributed in the area of feathered edge and at the smear side of body-feathered edge area in blood films. SEM ruled out the possibility of an optical illusion or an accidental overlap. qRBCs are associated with ageing of dogs, total leukocyte and neutrophil counts, and RBC anisocytosis, polychromasia, and Howell-Jolly bodies. Few hypotheses were discussed to explain the origin and meaning of this RBC arrangement.


1977 ◽  
Vol 109 (3) ◽  
pp. 477-479
Author(s):  
J. J. B. Smith ◽  
W. G. Friend

Special techniques are necessary to study the morphology of complex chitinous structures such as insect mouthparts. Many of the details are beyond the resolution of light microscopy, and the methods of conventional electron microscopy do not include the efficient production of serial sections for reconstruction. Although the scanning electron microscope (SEM) permits detailed observation of 3-dimensional surfaces, it cannot see internal surfaces and under complex folds, nor can it readily show the thickness of solid structures. To study the details of the stylet tips of the bug Rhodnius prolixus (Stål) several techniques were tried. Initially, specimens had been embedded in paraffin wax, sectioned, dewaxed, and prepared for the scanning electron microscope. Because of difficulties in sectioning the hard stylets and poor preservation of fine structure, this method was abandoned in favour of one using thick sections (2 μm) of material embedded in a mixture of Epon and Araldite.


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